diff --git a/NEWS.md b/NEWS.md
index 14f7ed779371c3..26b451be15c06a 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -242,13 +242,13 @@ details of the default gems or bundled gems.
     * Kernel#caller, Thread::Backtrace::Location’s methods, etc. are also changed accordingly.
 
         Old:
-        ```
+        ```text
         test.rb:1:in `foo': undefined method `time' for an instance of Integer
                 from test.rb:2:in `<main>'
         ```
 
         New:
-        ```
+        ```text
         test.rb:1:in 'Object#foo': undefined method 'time' for an instance of Integer
                 from test.rb:2:in '<main>'
         ```
@@ -259,21 +259,24 @@ details of the default gems or bundled gems.
     * Other keys now have spaces around `=>`: `'{"user" => 1}'`, while previously they didn't: `'{"user"=>1}'`
 
 * Kernel#Float() now accepts a decimal string with decimal part omitted. [[Feature #20705]]
-  ```
+
+  ```rb
   Float("1.")    #=> 1.0 (previously, an ArgumentError was raised)
   Float("1.E-1") #=> 0.1 (previously, an ArgumentError was raised)
   ```
 
 * String#to_f now accepts a decimal string with decimal part omitted. [[Feature #20705]]
   Note that the result changes when an exponent is specified.
-  ```
+
+  ```rb
   "1.".to_f    #=> 1.0
   "1.E-1".to_f #=> 0.1 (previously, 1.0 was returned)
   ```
 
 * Object#singleton_method now returns methods in modules prepended to or included in the
   receiver's singleton class. [[Bug #20620]]
-  ```
+
+  ```rb
   o = Object.new
   o.extend(Module.new{def a = 1})
   o.singleton_method(:a).call #=> 1
@@ -288,17 +291,17 @@ details of the default gems or bundled gems.
 * Net::HTTP
 
     * Removed the following deprecated constants:
-        `Net::HTTP::ProxyMod`
-        `Net::NetPrivate::HTTPRequest`
-        `Net::HTTPInformationCode`
-        `Net::HTTPSuccessCode`
-        `Net::HTTPRedirectionCode`
-        `Net::HTTPRetriableCode`
-        `Net::HTTPClientErrorCode`
-        `Net::HTTPFatalErrorCode`
-        `Net::HTTPServerErrorCode`
-        `Net::HTTPResponseReceiver`
-        `Net::HTTPResponceReceiver`
+        * `Net::HTTP::ProxyMod`
+        * `Net::NetPrivate::HTTPRequest`
+        * `Net::HTTPInformationCode`
+        * `Net::HTTPSuccessCode`
+        * `Net::HTTPRedirectionCode`
+        * `Net::HTTPRetriableCode`
+        * `Net::HTTPClientErrorCode`
+        * `Net::HTTPFatalErrorCode`
+        * `Net::HTTPServerErrorCode`
+        * `Net::HTTPResponseReceiver`
+        * `Net::HTTPResponceReceiver`
 
       These constants were deprecated from 2012.
 
diff --git a/benchmark/README.md b/benchmark/README.md
index e11381cad93e2c..6dc4bf8d1e759f 100644
--- a/benchmark/README.md
+++ b/benchmark/README.md
@@ -26,7 +26,7 @@ benchmark-driver benchmark/*.yml
 
 See also:
 
-```console
+```text
 Usage: benchmark-driver [options] RUBY|YAML...
     -r, --runner TYPE                Specify runner type: ips, time, memory, once, block (default: ips)
     -o, --output TYPE                Specify output type: compare, simple, markdown, record, all (default: compare)
diff --git a/doc/command_line/environment.md b/doc/command_line/environment.md
index 798074309294b6..8f6d595f6c2f25 100644
--- a/doc/command_line/environment.md
+++ b/doc/command_line/environment.md
@@ -151,14 +151,15 @@ nil
 Ruby code may also define warnings for certain categories;
 these are the default settings for the defined categories:
 
-```
+```ruby
 Warning[:experimental] # => true
 Warning[:deprecated]   # => false
 Warning[:performance]  # => false
 ```
 
 They may also be set:
-```
+
+```ruby
 Warning[:experimental] = false
 Warning[:deprecated]   = true
 Warning[:performance]  = true
diff --git a/doc/contributing/building_ruby.md b/doc/contributing/building_ruby.md
index 0acad0405c194c..5aad29ebfebfb8 100644
--- a/doc/contributing/building_ruby.md
+++ b/doc/contributing/building_ruby.md
@@ -32,7 +32,7 @@
     the OS default place, typically using Homebrew on macOS, pass the
     `--with-opt-dir` (or `--with-gmp-dir` for gmp) option to `configure`.
 
-    ``` shell
+    ```sh
     configure --with-opt-dir=$(brew --prefix gmp):$(brew --prefix jemalloc)
     ```
 
@@ -43,7 +43,7 @@
     latter environment variable is not embedded and is only used when
     building the extension libraries.
 
-    ``` shell
+    ```sh
     export CONFIGURE_ARGS=""
     for ext in openssl readline libyaml zlib; do
       CONFIGURE_ARGS="${CONFIGURE_ARGS} --with-$ext-dir=$(brew --prefix $ext)"
@@ -71,7 +71,7 @@
         Download the latest tarball from [Download Ruby] page and extract
         it. Example for Ruby 3.0.2:
 
-        ``` shell
+        ```sh
         tar -xzf ruby-3.0.2.tar.gz
         cd ruby-3.0.2
         ```
@@ -80,20 +80,20 @@
 
         Checkout the CRuby source code:
 
-        ``` shell
+        ```sh
         git clone https://github.com/ruby/ruby.git
         cd ruby
         ```
 
         Generate the configure file:
 
-        ``` shell
+        ```sh
         ./autogen.sh
         ```
 
 2. Create a `build` directory separate from the source directory:
 
-    ``` shell
+    ```sh
     mkdir build && cd build
     ```
 
@@ -102,13 +102,13 @@
 
 3. We'll install Ruby in `~/.rubies/ruby-master`, so create the directory:
 
-    ``` shell
+    ```sh
     mkdir ~/.rubies
     ```
 
 4. Run configure:
 
-    ``` shell
+    ```sh
     ../configure --prefix="${HOME}/.rubies/ruby-master"
     ```
 
@@ -117,7 +117,7 @@
 
 5. Build Ruby:
 
-    ``` shell
+    ```sh
     make
     ```
 
@@ -125,7 +125,7 @@
 
 7. Install Ruby:
 
-    ``` shell
+    ```sh
     make install
     ```
 
@@ -159,7 +159,7 @@ In GNU make[^caution-gmake-3] and BSD make implementations, to run a specific ma
 parallel, pass the flag `-j<number of processes>`. For instance, to run tests
 on 8 processes, use:
 
-``` shell
+```sh
 make test-all -j8
 ```
 
@@ -169,7 +169,7 @@ Having the right `--jobs` flag will ensure all processors are utilized when
 building software projects. To do this effectively, you can set `MAKEFLAGS` in
 your shell configuration/profile:
 
-``` shell
+```sh
 # On macOS with Fish shell:
 export MAKEFLAGS="--jobs "(sysctl -n hw.ncpu)
 
@@ -193,7 +193,7 @@ certain features.  It can be useful in Ruby development because it allows for
 faster build times. Miniruby is built before Ruby. A functional Miniruby is
 required to build Ruby. To build Miniruby:
 
-``` shell
+```sh
 make miniruby
 ```
 
@@ -215,7 +215,7 @@ following make targets:
 You should configure Ruby without optimization and other flags that may
 interfere with debugging:
 
-``` shell
+```sh
 ./configure --enable-debug-env optflags="-O0 -fno-omit-frame-pointer"
 ```
 
@@ -225,7 +225,7 @@ Using the address sanitizer (ASAN) is a great way to detect memory issues. It
 can detect memory safety issues in Ruby itself, and also in any C extensions
 compiled with and loaded into a Ruby compiled with ASAN.
 
-``` shell
+```sh
 ./autogen.sh
 mkdir build && cd build
 ../configure CC=clang-18 cflags="-fsanitize=address -fno-omit-frame-pointer -DUSE_MN_THREADS=0" # and any other options you might like
@@ -239,7 +239,7 @@ two hours on my laptop); the `RUBY_TEST_TIMEOUT_SCALE` and
 `SYNTAX_SUGEST_TIMEOUT` variables are required to make sure tests don't
 spuriously fail with timeouts when in fact they're just slow.
 
-``` shell
+```sh
 RUBY_TEST_TIMEOUT_SCALE=5 SYNTAX_SUGGEST_TIMEOUT=600 make check
 ```
 
@@ -274,7 +274,7 @@ Please note, however, the following caveats!
 
 You need to be able to use gcc (gcov) and lcov visualizer.
 
-``` shell
+```sh
 ./autogen.sh
 ./configure --enable-gcov
 make
diff --git a/doc/contributing/documentation_guide.md b/doc/contributing/documentation_guide.md
index f93fc411652e96..a4df55e2449c5a 100644
--- a/doc/contributing/documentation_guide.md
+++ b/doc/contributing/documentation_guide.md
@@ -95,7 +95,7 @@ involving new files `doc/*.rdoc`:
 
     Example:
 
-    ```
+    ```c
     /*
      *  call-seq:
      *    each_byte {|byte| ... } -> self
@@ -173,12 +173,13 @@ Code that is a simple string should include the quote marks.
 Most often, the name of a class, module, or method
 is auto-linked:
 
-```
+```rdoc
 - Float.
 - Enumerable.
 - File.new
 - File#read.
 ```
+
 renders as:
 
 > - Float.
@@ -189,7 +190,7 @@ renders as:
 In general, \RDoc's auto-linking should not be suppressed.
 For example, we should write just plain _Float_ (which is auto-linked):
 
-```
+```rdoc
 Returns a Float.
 ```
 
@@ -200,13 +201,13 @@ which renders as:
 However, _do_ suppress auto-linking when the word in question
 does not refer to a Ruby entity (e.g., some uses of _Class_ or _English_):
 
-```
+```rdoc
 \Class variables can be tricky.
 ```
 
 renders as:
 
-> \\Class variables can be tricky.
+> Class variables can be tricky.
 
 Also, _do_ suppress auto-linking when the word in question
 refers to the current document
@@ -216,7 +217,7 @@ In this case you may consider forcing the name to
 [monofont](rdoc-ref:RDoc::MarkupReference@Monofont),
 which suppresses auto-linking, and also emphasizes that the word is a class name:
 
-```
+```rdoc
 A +Float+ object represents ....
 ```
 
@@ -231,7 +232,7 @@ you might write simply the lowercase _array_.
 
 Instead of:
 
-```
+```rdoc
 For an empty Array, ....
 ```
 
@@ -241,7 +242,7 @@ which renders as:
 
 you might write:
 
-```
+```rdoc
 For an empty array, ....
 ```
 
@@ -398,13 +399,13 @@ the method accepts, so those need to be documented using \RDoc directive
 
 For a singleton method, use the form:
 
-```
+```rdoc
 class_name.method_name(method_args) {|block_args| ... } -> return_type
 ```
 
 Example:
 
-```
+```rdoc
 *  call-seq:
 *    Hash.new(default_value = nil) -> new_hash
 *    Hash.new {|hash, key| ... } -> new_hash
@@ -413,19 +414,20 @@ Example:
 For an instance method, use the form
 (omitting any prefix, just as RDoc does for a Ruby-coded method):
 
-```
+```rdoc
 method_name(method_args) {|block_args| ... } -> return_type
 ```
+
 For example, in Array, use:
 
-```
+```rdoc
 *  call-seq:
 *    count -> integer
 *    count(obj) -> integer
 *    count {|element| ... } -> integer
 ```
 
-```
+```rdoc
 *  call-seq:
 *    <=> other -> -1, 0, 1, or nil
 ```
@@ -433,7 +435,7 @@ For example, in Array, use:
 For a binary-operator style method (e.g., Array#&),
 cite `self` in the call-seq (not, e.g., `array` or `receiver`):
 
-```
+```rdoc
 *  call-seq:
 *    self & other_array -> new_array
 ```
@@ -449,7 +451,7 @@ Arguments:
       or an explicit argument, use a `call-seq` with optional arguments.
       For example, use:
 
-        ```
+        ```rdoc
         *  call-seq:
         *    respond_to?(symbol, include_all = false) -> true or false
         ```
@@ -458,7 +460,7 @@ Arguments:
       use a `call-seq` with separate lines.
       For example, in Enumerable, use:
 
-        ```
+        ```rdoc
         *  call-seq:
         *    max    -> element
         *    max(n) -> array
@@ -472,7 +474,7 @@ Block:
 - If the method accepts a block, but returns an Enumerator when the block is omitted,
   the `call-seq` should show both forms:
 
-    ```
+    ```rdoc
     *  call-seq:
     *    array.select {|element| ... } -> new_array
     *    array.select -> new_enumerator
@@ -505,9 +507,7 @@ an entire paragraph.
 
 For `Array#count`, the synopsis is:
 
-```
-Returns a count of specified elements.
-```
+> Returns a count of specified elements.
 
 This is great as it is short and descriptive.  Avoid documenting
 too much in the synopsis, stick to the most important information
@@ -550,7 +550,7 @@ but return a new Enumerator if the block is not given;
 in that case, do not provide an example,
 but do state the fact (with the auto-linking uppercase Enumerator):
 
-```
+```rdoc
 *  With no block given, returns a new Enumerator.
 ```
 
diff --git a/doc/contributing/making_changes_to_stdlibs.md b/doc/contributing/making_changes_to_stdlibs.md
index 3b33092fead20f..721ba842896a25 100644
--- a/doc/contributing/making_changes_to_stdlibs.md
+++ b/doc/contributing/making_changes_to_stdlibs.md
@@ -14,7 +14,7 @@ You can find the list of maintainers [here](https://docs.ruby-lang.org/en/master
 
 First, install its dependencies using:
 
-```
+```shell
 bundle install
 ```
 
@@ -22,7 +22,7 @@ bundle install
 
 If the library has a `/ext` directory, it has C files that you need to compile with:
 
-```
+```shell
 bundle exec rake compile
 ```
 
@@ -32,18 +32,18 @@ All standard libraries use [test-unit](https://github.com/test-unit/test-unit) a
 
 To run all tests:
 
-```
+```shell
 bundle exec rake test
 ```
 
 To run a single test file:
 
-```
+```shell
 bundle exec rake test TEST="test/test_foo.rb"
 ```
 
 To run a single test case:
 
-```
+```shell
 bundle exec rake test TEST="test/test_foo.rb" TESTOPS="--name=/test_mytest/"
 ```
diff --git a/doc/contributing/testing_ruby.md b/doc/contributing/testing_ruby.md
index dfb7fb3a658161..ca6a991917bf13 100644
--- a/doc/contributing/testing_ruby.md
+++ b/doc/contributing/testing_ruby.md
@@ -10,38 +10,38 @@ We can run any of the make scripts [in parallel](building_ruby.md#label-Running+
 
     This is a small test suite that runs on Miniruby (see [building Ruby](building_ruby.md#label-Miniruby+vs+Ruby)). We can run it with:
 
-    ```
+    ```sh
     make btest
     ```
 
     To run it with logs, we can use:
 
-    ```
+    ```sh
     make btest OPTS=-v
     ```
 
     To run individual bootstrap tests, we can either specify a list of filenames or use the `--sets` flag in the variable `BTESTS`:
 
-    ```
-    make btest BTESTS="bootstraptest/test_fork.rb bootstraptest/tes_gc.rb"
+    ```sh
+    make btest BTESTS="../bootstraptest/test_fork.rb ../bootstraptest/test_gc.rb"
     make btest BTESTS="--sets=fork,gc"
     ```
 
     If we want to run the bootstrap test suite on Ruby (not Miniruby), we can use:
 
-    ```
+    ```sh
     make test
     ```
 
     To run it with logs, we can use:
 
-    ```
+    ```sh
     make test OPTS=-v
     ```
 
     To run a file or directory with GNU make, we can use:
 
-    ```
+    ```sh
     make test/ruby/test_foo.rb
     make test/ruby/test_foo.rb TESTOPTS="-n /test_bar/"
     ```
@@ -50,44 +50,44 @@ We can run any of the make scripts [in parallel](building_ruby.md#label-Running+
 
     This is a more comprehensive test suite that runs on Ruby. We can run it with:
 
-    ```
+    ```sh
     make test-all
     ```
 
     We can run a specific test directory in this suite using the `TESTS` option, for example:
 
-    ```
+    ```sh
     make test-all TESTS=test/rubygems
     ```
 
     We can run a specific test file in this suite by also using the `TESTS` option, for example:
 
-    ```
+    ```sh
     make test-all TESTS=test/ruby/test_array.rb
     ```
 
     We can run a specific test in this suite using the `TESTS` option, specifying
     first the file name, and then the test name, prefixed with `--name`. For example:
 
-    ```
+    ```sh
     make test-all TESTS="../test/ruby/test_alias.rb --name=TestAlias#test_alias_with_zsuper_method"
     ```
 
     To run these specs with logs, we can use:
 
-    ```
+    ```sh
     make test-all TESTS=-v
     ```
 
     We can display the help of the `TESTS` option:
 
-    ```
+    ```sh
     make test-all TESTS=--help
     ```
 
     If we would like to run the `test/`, `bootstraptest/` and `spec/` test suites (the `spec/` is explained in a later section), we can run
 
-    ```
+    ```sh
     make check
     ```
 
@@ -95,37 +95,37 @@ We can run any of the make scripts [in parallel](building_ruby.md#label-Running+
 
     This is a test suite that exists in [the Ruby spec repository](https://github.com/ruby/spec) and is mirrored into the `spec/ruby` directory in the Ruby repository. It tests the behavior of the Ruby programming language. We can run this using:
 
-    ```
+    ```sh
     make test-spec
     ```
 
     To run a specific directory, we can use `SPECOPTS` to specify the directory:
 
-    ```
+    ```sh
     make test-spec SPECOPTS=spec/ruby/core/array
     ```
 
     To run a specific file, we can also use `SPECOPTS` to specify the file:
 
-    ```
+    ```sh
     make test-spec SPECOPTS=spec/ruby/core/array/any_spec.rb
     ```
 
     To run a specific test, we can use the `--example` flag to match against the test name:
 
-    ```
+    ```sh
     make test-spec SPECOPTS="../spec/ruby/core/array/any_spec.rb --example='is false if the array is empty'"
     ```
 
     To run these specs with logs, we can use:
 
-    ```
+    ```sh
     make test-spec SPECOPTS=-Vfs
     ```
 
     To run a ruby-spec file or directory with GNU make, we can use
 
-    ```
+    ```sh
     make spec/ruby/core/foo/bar_spec.rb
     ```
 
@@ -133,13 +133,13 @@ We can run any of the make scripts [in parallel](building_ruby.md#label-Running+
 
     The bundler test suite exists in [the RubyGems repository](https://github.com/rubygems/rubygems/tree/master/bundler/spec) and is mirrored into the `spec/bundler` directory in the Ruby repository. We can run this using:
 
-    ```
+    ```sh
     make test-bundler
     ```
 
     To run a specific bundler spec file, we can use `BUNDLER_SPECS` as follows:
 
-    ```
+    ```sh
     make test-bundler BUNDLER_SPECS=commands/exec_spec.rb
     ```
 
@@ -149,7 +149,7 @@ We can run any of the make scripts [in parallel](building_ruby.md#label-Running+
 
 If we see failing tests related to the zlib library on s390x CPU architecture, we can run the test suites with `DFLTCC=0` to pass:
 
-```
+```sh
 DFLTCC=0 make check
 ```
 
diff --git a/doc/exceptions.md b/doc/exceptions.md
index ae03438519b1fa..65aa2bca6cfa56 100644
--- a/doc/exceptions.md
+++ b/doc/exceptions.md
@@ -9,7 +9,7 @@ and may need to be handled.
 Code throughout the Ruby core, Ruby standard library, and Ruby gems generates exceptions
 in certain circumstances:
 
-```
+```rb
 File.open('nope.txt') # Raises Errno::ENOENT: "No such file or directory"
 ```
 
@@ -38,7 +38,7 @@ and may prevent the program from exiting.
 
 A simple example:
 
-```
+```rb
 begin
   raise 'Boom!'                # Raises an exception, transfers control.
   puts 'Will not get here.'
@@ -50,7 +50,7 @@ puts 'Got here.'
 
 Output:
 
-```
+```text
 Rescued an exception.
 Got here.
 ```
@@ -94,7 +94,7 @@ The rescue clause rescues both the specified class
 (or StandardError if none given) or any of its subclasses;
 see [Built-In Exception Class Hierarchy](rdoc-ref:Exception@Built-In+Exception+Class+Hierarchy).
 
-```
+```rb
 begin
   1 / 0 # Raises ZeroDivisionError, a subclass of StandardError.
 rescue
@@ -104,7 +104,7 @@ end
 
 Output:
 
-```
+```text
 Rescued ZeroDivisionError
 ```
 
@@ -113,7 +113,7 @@ only that class (or one of its subclasses) is rescued;
 this example exits with a ZeroDivisionError,
 which was not rescued because it is not ArgumentError or one of its subclasses:
 
-```
+```rb
 begin
   1 / 0
 rescue ArgumentError
@@ -125,7 +125,7 @@ A `rescue` statement may specify multiple classes,
 which means that its code rescues an exception
 of any of the given classes (or their subclasses):
 
-```
+```rb
 begin
   1 / 0
 rescue FloatDomainError, ZeroDivisionError
@@ -139,7 +139,7 @@ An exception handler may contain multiple rescue clauses;
 in that case, the first clause that rescues the exception does so,
 and those before and after are ignored:
 
-```
+```rb
 begin
   Dir.open('nosuch')
 rescue Errno::ENOTDIR
@@ -151,7 +151,7 @@ end
 
 Output:
 
-```
+```text
 Rescued Errno::ENOENT
 ```
 
@@ -161,7 +161,7 @@ A `rescue` statement may specify a variable
 whose value becomes the rescued exception
 (an instance of Exception or one of its subclasses:
 
-```
+```rb
 begin
   1 / 0
 rescue => x
@@ -172,7 +172,7 @@ end
 
 Output:
 
-```
+```text
 ZeroDivisionError
 divided by 0
 ```
@@ -188,7 +188,7 @@ there:
 
 Example:
 
-```
+```rb
 begin
   1 / 0
 rescue
@@ -199,7 +199,7 @@ end
 
 Output:
 
-```
+```text
 #<ZeroDivisionError: divided by 0>
 ["t.rb:2:in `/'", "t.rb:2:in `<main>'"]
 ```
@@ -212,7 +212,7 @@ elsewhere, the method returns `nil`.
 
 Example:
 
-```
+```rb
 begin
   raise('Boom 0')
 rescue => x0
@@ -232,7 +232,7 @@ end
 
 Output:
 
-```
+```text
 Exception: #<RuntimeError: Boom 0>;  $!: #<RuntimeError: Boom 0>;  cause: nil.
 Exception: #<RuntimeError: Boom 1>;  $!: #<RuntimeError: Boom 1>;  cause: #<RuntimeError: Boom 0>.
 Exception: #<RuntimeError: Boom 2>;  $!: #<RuntimeError: Boom 2>;  cause: #<RuntimeError: Boom 1>.
@@ -246,7 +246,7 @@ The `else` clause:
 - Contains code that is to be executed if no exception is raised in the begin clause.
 - Ends with the first following `ensure` or `end` statement.
 
-```
+```rb
 begin
   puts 'Begin.'
 rescue
@@ -258,7 +258,7 @@ end
 
 Output:
 
-```
+```text
 Begin.
 No exception raised.
 ```
@@ -273,7 +273,7 @@ The ensure clause:
   and regardless of whether a raised exception is handled.
 - Ends with the first following `end` statement.
 
-```
+```rb
 def foo(boom: false)
   puts 'Begin.'
   raise 'Boom!' if boom
@@ -291,7 +291,7 @@ foo(boom: false)
 
 Output:
 
-```
+```text
 Begin.
 Rescued an exception!
 Always do this.
@@ -314,7 +314,7 @@ An exception handler may also be implemented as:
 
 - A method body:
 
-    ```
+    ```rb
     def foo(boom: false) # Serves as beginning of exception handler.
       puts 'Begin.'
       raise 'Boom!' if boom
@@ -327,7 +327,7 @@ An exception handler may also be implemented as:
 
 - A block:
 
-    ```
+    ```rb
     Dir.chdir('.') do |dir| # Serves as beginning of exception handler.
       raise 'Boom!'
     rescue
@@ -349,7 +349,7 @@ a rescuing clause:
   - Calls method `raise` with no argument,
     which raises the rescued exception:
 
-```
+```rb
 begin
   1 / 0
 rescue ZeroDivisionError
@@ -360,7 +360,7 @@ end
 
 Output:
 
-```
+```text
 ruby t.rb
 t.rb:2:in `/': divided by 0 (ZeroDivisionError)
         from t.rb:2:in `<main>'
@@ -374,7 +374,7 @@ for example, if it must access a possibly-volatile resource
 it can be useful to try the access more than once
 (in the hope that it may become available):
 
-```
+```rb
 retries = 0
 begin
   puts "Try ##{retries}."
@@ -391,7 +391,7 @@ rescue
 end
 ```
 
-```
+```text
 Try #0.
 Rescued retry #0.
 Retrying
@@ -419,7 +419,7 @@ Each should be a subclass of one of the built-in exception classes
 (commonly StandardError or RuntimeError);
 see [Built-In Exception Class Hierarchy](rdoc-ref:Exception@Built-In+Exception+Class+Hierarchy).
 
-```
+```rb
 class MyException < StandardError; end
 ```
 
diff --git a/doc/fiber.md b/doc/fiber.md
index a334faf7396187..2bc1ff96b2501a 100644
--- a/doc/fiber.md
+++ b/doc/fiber.md
@@ -6,7 +6,7 @@ Fibers provide a mechanism for cooperative concurrency.
 
 Fibers execute a user-provided block. During the execution, the block may call `Fiber.yield` or `Fiber.transfer` to switch to another fiber. `Fiber#resume` is used to continue execution from the point where `Fiber.yield` was called.
 
-``` ruby
+```rb
 #!/usr/bin/env ruby
 
 puts "1: Start program."
@@ -38,13 +38,13 @@ instrumentation.
 
 To set the scheduler for the current thread:
 
-``` ruby
+```rb
 Fiber.set_scheduler(MyScheduler.new)
 ```
 
 When the thread exits, there is an implicit call to `set_scheduler`:
 
-``` ruby
+```rb
 Fiber.set_scheduler(nil)
 ```
 
@@ -60,7 +60,7 @@ no changes.
 
 This is the interface you need to implement.
 
-``` ruby
+```rb
 class Scheduler
   # Wait for the specified process ID to exit.
   # This hook is optional.
@@ -166,7 +166,7 @@ program.
 
 Fibers can be used to create non-blocking execution contexts.
 
-``` ruby
+```rb
 Fiber.new do
   puts Fiber.current.blocking? # false
 
@@ -184,7 +184,7 @@ end.resume
 We also introduce a new method which simplifies the creation of these
 non-blocking fibers:
 
-``` ruby
+```rb
 Fiber.schedule do
   puts Fiber.current.blocking? # false
 end
@@ -196,7 +196,7 @@ fibers.
 
 You can also create blocking execution contexts:
 
-``` ruby
+```rb
 Fiber.new(blocking: true) do
   # Won't use the scheduler:
   sleep(n)
diff --git a/doc/ractor.md b/doc/ractor.md
index 7a69e839de7a27..6ed0eadfcd26d9 100644
--- a/doc/ractor.md
+++ b/doc/ractor.md
@@ -212,7 +212,7 @@ For message sending and receiving, there are two types of APIs: push type and pu
 
 Each Ractor has _incoming-port_ and _outgoing-port_. Incoming-port is connected to the infinite sized incoming queue.
 
-```
+```text
                   Ractor r
                  +-------------------------------------------+
                  | incoming                         outgoing |
@@ -258,8 +258,7 @@ r.take      # Receive from r's outgoing port
 
 The last example shows the following ractor network.
 
-```
-
+```text
   +------+        +---+
   * main |------> * r *---+
   +------+        +---+   |
@@ -875,17 +874,17 @@ p Ractor.select(*rs, Ractor.current) #=> [:receive, "r0r10r9r8r7r6r5r4r3r2r1"]
 r.send "e0"
 p Ractor.select(*rs, Ractor.current)
 #=>
-#<Thread:0x000056262de28bd8 run> terminated with exception (report_on_exception is true):
-Traceback (most recent call last):
-        2: from /home/ko1/src/ruby/trunk/test.rb:7:in `block (2 levels) in <main>'
-        1: from /home/ko1/src/ruby/trunk/test.rb:7:in `loop'
-/home/ko1/src/ruby/trunk/test.rb:9:in `block (3 levels) in <main>': unhandled exception
-Traceback (most recent call last):
-        2: from /home/ko1/src/ruby/trunk/test.rb:7:in `block (2 levels) in <main>'
-        1: from /home/ko1/src/ruby/trunk/test.rb:7:in `loop'
-/home/ko1/src/ruby/trunk/test.rb:9:in `block (3 levels) in <main>': unhandled exception
-        1: from /home/ko1/src/ruby/trunk/test.rb:21:in `<main>'
-<internal:ractor>:69:in `select': thrown by remote Ractor. (Ractor::RemoteError)
+# <Thread:0x000056262de28bd8 run> terminated with exception (report_on_exception is true):
+# Traceback (most recent call last):
+#         2: from /home/ko1/src/ruby/trunk/test.rb:7:in `block (2 levels) in <main>'
+#         1: from /home/ko1/src/ruby/trunk/test.rb:7:in `loop'
+# /home/ko1/src/ruby/trunk/test.rb:9:in `block (3 levels) in <main>': unhandled exception
+# Traceback (most recent call last):
+#         2: from /home/ko1/src/ruby/trunk/test.rb:7:in `block (2 levels) in <main>'
+#         1: from /home/ko1/src/ruby/trunk/test.rb:7:in `loop'
+# /home/ko1/src/ruby/trunk/test.rb:9:in `block (3 levels) in <main>': unhandled exception
+#         1: from /home/ko1/src/ruby/trunk/test.rb:21:in `<main>'
+# <internal:ractor>:69:in `select': thrown by remote Ractor. (Ractor::RemoteError)
 ```
 
 ```ruby
diff --git a/doc/ruby/option_dump.md b/doc/ruby/option_dump.md
index 331c248e507ace..cb5fb02dab961c 100644
--- a/doc/ruby/option_dump.md
+++ b/doc/ruby/option_dump.md
@@ -89,7 +89,7 @@ The supported dump items:
 
 - `yydebug`: Debugging information from yacc parser generator:
 
-    ```sh
+    ```text
     $ ruby --dump=yydebug t.rb
     Starting parse
     Entering state 0
diff --git a/doc/ruby/options.md b/doc/ruby/options.md
index c4d7c92a1ceb9c..6e0278e143f328 100644
--- a/doc/ruby/options.md
+++ b/doc/ruby/options.md
@@ -320,9 +320,9 @@ See also:
 
 ### `-n`: Run Program in `gets` Loop
 
-Option `-n` runs your program in a Kernel#gets loop:
+Option `-n` runs your program in a `Kernel#gets` loop:
 
-```
+```ruby
 while gets
   # Your Ruby code.
 end
@@ -493,14 +493,15 @@ nil
 Ruby code may also define warnings for certain categories;
 these are the default settings for the defined categories:
 
-```
+```rb
 Warning[:experimental] # => true
 Warning[:deprecated]   # => false
 Warning[:performance]  # => false
 ```
 
 They may also be set:
-```
+
+```rb
 Warning[:experimental] = false
 Warning[:deprecated]   = true
 Warning[:performance]  = true
diff --git a/doc/strscan/helper_methods.md b/doc/strscan/helper_methods.md
index 6555a2ce66159f..9fb1d79bba91f7 100644
--- a/doc/strscan/helper_methods.md
+++ b/doc/strscan/helper_methods.md
@@ -10,7 +10,7 @@ Display scanner's situation:
 - Character position (`#charpos`)
 - Target string (`#rest`) and size (`#rest_size`).
 
-```
+```rb
 scanner = StringScanner.new('foobarbaz')
 scanner.scan(/foo/)
 put_situation(scanner)
@@ -25,7 +25,7 @@ put_situation(scanner)
 
 Display the scanner's match values:
 
-```
+```rb
 scanner = StringScanner.new('Fri Dec 12 1975 14:39')
 pattern = /(?<wday>\w+) (?<month>\w+) (?<day>\d+) /
 scanner.match?(pattern)
@@ -53,7 +53,7 @@ put_match_values(scanner)
 
 Returns whether the scanner's match values are all properly cleared:
 
-```
+```rb
 scanner = StringScanner.new('foobarbaz')
 match_values_cleared?(scanner) # => true
 put_match_values(scanner)
@@ -75,7 +75,7 @@ match_values_cleared?(scanner) # => false
 
 ## The Code
 
-```
+```rb
 def put_situation(scanner)
   puts '# Situation:'
   puts "#   pos:       #{scanner.pos}"
@@ -83,9 +83,7 @@ def put_situation(scanner)
   puts "#   rest:      #{scanner.rest.inspect}"
   puts "#   rest_size: #{scanner.rest_size}"
 end
-```
 
-```
 def put_match_values(scanner)
   puts '# Basic match values:'
   puts "#   matched?:       #{scanner.matched?}"
@@ -109,9 +107,7 @@ def put_match_values(scanner)
     end
   end
 end
-```
 
-```
 def match_values_cleared?(scanner)
   scanner.matched? == false &&
     scanner.matched_size.nil? &&
diff --git a/doc/strscan/methods/get_byte.md b/doc/strscan/methods/get_byte.md
index 2f23be189947bd..3208d77158b342 100644
--- a/doc/strscan/methods/get_byte.md
+++ b/doc/strscan/methods/get_byte.md
@@ -10,7 +10,7 @@ Returns the next byte, if available:
     - Increments the [byte position][2].
     - Adjusts the [character position][7].
 
-    ```
+    ```rb
     scanner = StringScanner.new(HIRAGANA_TEXT)
     # => #<StringScanner 0/15 @ "\xE3\x81\x93\xE3\x82...">
     scanner.string                                   # => "こんにちは"
@@ -24,7 +24,7 @@ Returns the next byte, if available:
 
 - Otherwise, returns `nil`, and does not change the positions.
 
-    ```
+    ```rb
     scanner.terminate
     [scanner.get_byte, scanner.pos, scanner.charpos] # => [nil, 15, 5]
     ```
diff --git a/doc/strscan/methods/get_charpos.md b/doc/strscan/methods/get_charpos.md
index f77563c860029f..954fcf5b44e599 100644
--- a/doc/strscan/methods/get_charpos.md
+++ b/doc/strscan/methods/get_charpos.md
@@ -5,7 +5,7 @@ Returns the [character position][7] (initially zero),
 which may be different from the [byte position][2]
 given by method #pos:
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string # => "こんにちは"
 scanner.getch  # => "こ" # 3-byte character.
diff --git a/doc/strscan/methods/get_pos.md b/doc/strscan/methods/get_pos.md
index 56bcef32745a01..81bbb2345e9268 100644
--- a/doc/strscan/methods/get_pos.md
+++ b/doc/strscan/methods/get_pos.md
@@ -4,7 +4,7 @@ call-seq:
 Returns the integer [byte position][2],
 which may be different from the [character position][7]:
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string  # => "こんにちは"
 scanner.pos     # => 0
diff --git a/doc/strscan/methods/getch.md b/doc/strscan/methods/getch.md
index b57732ad7c189f..3dd70e4c5be04a 100644
--- a/doc/strscan/methods/getch.md
+++ b/doc/strscan/methods/getch.md
@@ -12,7 +12,7 @@ if available:
     - Increments the [byte position][2]
       by the size (in bytes) of the character.
 
-    ```
+    ```rb
     scanner = StringScanner.new(HIRAGANA_TEXT)
     scanner.string                                # => "こんにちは"
     [scanner.getch, scanner.pos, scanner.charpos] # => ["こ", 3, 1]
@@ -27,7 +27,7 @@ if available:
   (that is, not at its beginning),
   behaves like #get_byte (returns a 1-byte character):
 
-    ```
+    ```rb
     scanner.pos = 1
     [scanner.getch, scanner.pos, scanner.charpos] # => ["\x81", 2, 2]
     [scanner.getch, scanner.pos, scanner.charpos] # => ["\x93", 3, 1]
@@ -37,7 +37,7 @@ if available:
 - If the [position][2] is at the end of the [stored string][1],
   returns `nil` and does not modify the positions:
 
-    ```
+    ```rb
     scanner.terminate
     [scanner.getch, scanner.pos, scanner.charpos] # => [nil, 15, 5]
     ```
diff --git a/doc/strscan/methods/scan.md b/doc/strscan/methods/scan.md
index 714fa9910afa5f..7cff36bb97e0b4 100644
--- a/doc/strscan/methods/scan.md
+++ b/doc/strscan/methods/scan.md
@@ -45,7 +45,7 @@ If the match fails:
 - Does not increment byte and character positions.
 - Clears match values.
 
-```
+```rb
 scanner.scan(/nope/)           # => nil
 match_values_cleared?(scanner) # => true
 ```
diff --git a/doc/strscan/methods/scan_until.md b/doc/strscan/methods/scan_until.md
index 3b7ff2c3a9b593..b98b2bd31b1197 100644
--- a/doc/strscan/methods/scan_until.md
+++ b/doc/strscan/methods/scan_until.md
@@ -46,7 +46,7 @@ If the match attempt fails:
 - Returns `nil`.
 - Does not update positions.
 
-```
+```rb
 scanner.scan_until(/nope/)     # => nil
 match_values_cleared?(scanner) # => true
 ```
diff --git a/doc/strscan/methods/set_pos.md b/doc/strscan/methods/set_pos.md
index 230177109cbc20..3b7abe65e3379a 100644
--- a/doc/strscan/methods/set_pos.md
+++ b/doc/strscan/methods/set_pos.md
@@ -9,7 +9,7 @@ Does not affect [match values][9].
 
 For non-negative `n`, sets the position to `n`:
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string  # => "こんにちは"
 scanner.pos = 3 # => 3
@@ -19,7 +19,7 @@ scanner.charpos # => 1
 
 For negative `n`, counts from the end of the [stored string][1]:
 
-```
+```rb
 scanner.pos = -9 # => -9
 scanner.pos      # => 6
 scanner.rest     # => "にちは"
diff --git a/doc/strscan/methods/skip_until.md b/doc/strscan/methods/skip_until.md
index 5187a4826fb2c7..b7dacf6da1ee13 100644
--- a/doc/strscan/methods/skip_until.md
+++ b/doc/strscan/methods/skip_until.md
@@ -10,7 +10,7 @@ If the match attempt succeeds:
 - Sets [match values][9].
 - Returns the size of the matched substring.
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string           # => "こんにちは"
 scanner.pos = 6
@@ -43,7 +43,7 @@ If the match attempt fails:
 - Clears match values.
 - Returns `nil`.
 
-```
+```rb
 scanner.skip_until(/nope/)     # => nil
 match_values_cleared?(scanner) # => true
 ```
diff --git a/doc/strscan/methods/terminate.md b/doc/strscan/methods/terminate.md
index fd557270996c5b..b03b37d2a289ab 100644
--- a/doc/strscan/methods/terminate.md
+++ b/doc/strscan/methods/terminate.md
@@ -7,7 +7,7 @@ returns +self+:
 - Sets both [positions][11] to end-of-stream.
 - Clears [match values][9].
 
-```
+```rb
 scanner = StringScanner.new(HIRAGANA_TEXT)
 scanner.string                 # => "こんにちは"
 scanner.scan_until(/に/)
diff --git a/doc/strscan/strscan.md b/doc/strscan/strscan.md
index 558568dc437995..dea87e0d43de8c 100644
--- a/doc/strscan/strscan.md
+++ b/doc/strscan/strscan.md
@@ -1,7 +1,7 @@
 \Class `StringScanner` supports processing a stored string as a stream;
 this code creates a new `StringScanner` object with string `'foobarbaz'`:
 
-```
+```rb
 require 'strscan'
 scanner = StringScanner.new('foobarbaz')
 ```
@@ -10,13 +10,13 @@ scanner = StringScanner.new('foobarbaz')
 
 All examples here assume that `StringScanner` has been required:
 
-```
+```rb
 require 'strscan'
 ```
 
 Some examples here assume that these constants are defined:
 
-```
+```rb
 MULTILINE_TEXT = <<~EOT
 Go placidly amid the noise and haste,
 and remember what peace there may be in silence.
@@ -45,7 +45,7 @@ This code creates a `StringScanner` object
 (we'll call it simply a _scanner_),
 and shows some of its basic properties:
 
-```
+```rb
 scanner = StringScanner.new('foobarbaz')
 scanner.string # => "foobarbaz"
 put_situation(scanner)
@@ -138,7 +138,7 @@ To get or set the byte position:
 Many methods use the byte position as the basis for finding matches;
 many others set, increment, or decrement the byte position:
 
-```
+```rb
 scanner = StringScanner.new('foobar')
 scanner.pos # => 0
 scanner.scan(/foo/) # => "foo" # Match found.
@@ -176,7 +176,7 @@ see:
 
 Example (string includes multi-byte characters):
 
-```
+```rb
 scanner = StringScanner.new(ENGLISH_TEXT) # Five 1-byte characters.
 scanner.concat(HIRAGANA_TEXT)             # Five 3-byte characters
 scanner.string # => "Helloこんにちは"       # Twenty bytes in all.
@@ -216,7 +216,7 @@ and its size is returned by method #rest_size.
 
 Examples:
 
-```
+```rb
 scanner = StringScanner.new('foobarbaz')
 put_situation(scanner)
 # Situation:
@@ -430,7 +430,7 @@ See examples below.
 
 Successful basic match attempt (no captures):
 
-```
+```rb
 scanner = StringScanner.new('foobarbaz')
 scanner.exist?(/bar/)
 put_match_values(scanner)
@@ -452,7 +452,7 @@ put_match_values(scanner)
 
 Failed basic match attempt (no captures);
 
-```
+```rb
 scanner = StringScanner.new('foobarbaz')
 scanner.exist?(/nope/)
 match_values_cleared?(scanner) # => true
@@ -460,7 +460,7 @@ match_values_cleared?(scanner) # => true
 
 Successful unnamed capture match attempt:
 
-```
+```rb
 scanner = StringScanner.new('foobarbazbatbam')
 scanner.exist?(/(foo)bar(baz)bat(bam)/)
 put_match_values(scanner)
@@ -486,7 +486,7 @@ put_match_values(scanner)
 Successful named capture match attempt;
 same as unnamed above, except for #named_captures:
 
-```
+```rb
 scanner = StringScanner.new('foobarbazbatbam')
 scanner.exist?(/(?<x>foo)bar(?<y>baz)bat(?<z>bam)/)
 scanner.named_captures # => {"x"=>"foo", "y"=>"baz", "z"=>"bam"}
@@ -494,7 +494,7 @@ scanner.named_captures # => {"x"=>"foo", "y"=>"baz", "z"=>"bam"}
 
 Failed unnamed capture match attempt:
 
-```
+```rb
 scanner = StringScanner.new('somestring')
 scanner.exist?(/(foo)bar(baz)bat(bam)/)
 match_values_cleared?(scanner) # => true
@@ -503,7 +503,7 @@ match_values_cleared?(scanner) # => true
 Failed named capture match attempt;
 same as unnamed above, except for #named_captures:
 
-```
+```rb
 scanner = StringScanner.new('somestring')
 scanner.exist?(/(?<x>foo)bar(?<y>baz)bat(?<z>bam)/)
 match_values_cleared?(scanner) # => false
@@ -518,7 +518,7 @@ which determines the meaning of `'\A'`:
 
 * `false` (the default): matches the current byte position.
 
-    ```
+    ```rb
     scanner = StringScanner.new('foobar')
     scanner.scan(/\A./) # => "f"
     scanner.scan(/\A./) # => "o"
@@ -529,7 +529,7 @@ which determines the meaning of `'\A'`:
 * `true`: matches the beginning of the target substring;
   never matches unless the byte position is zero:
 
-    ```
+    ```rb
     scanner = StringScanner.new('foobar', fixed_anchor: true)
     scanner.scan(/\A./) # => "f"
     scanner.scan(/\A./) # => nil
diff --git a/doc/windows.md b/doc/windows.md
index b802edf1701f1a..b1f9f5a670d4e0 100644
--- a/doc/windows.md
+++ b/doc/windows.md
@@ -16,7 +16,7 @@ editor.
 
 Ruby core development can be done either in Windows `cmd` like:
 
-```
+```batch
 ridk enable ucrt64
 
 pacman -S --needed %MINGW_PACKAGE_PREFIX%-openssl %MINGW_PACKAGE_PREFIX%-libyaml %MINGW_PACKAGE_PREFIX%-libffi
@@ -34,7 +34,7 @@ make
 
 or in MSYS2 `bash` like:
 
-```
+```bash
 ridk enable ucrt64
 bash
 
@@ -85,14 +85,14 @@ make
 
     You can use [scoop](https://scoop.sh/) to install them like:
 
-    ```
+    ```batch
     scoop install git sed ruby
     ```
 
 5.  You need to install required libraries using [vcpkg](https://vcpkg.io/) on
     directory of ruby repository like:
 
-    ```
+    ```batch
     vcpkg --triplet x64-windows install
     ```
 
@@ -140,13 +140,13 @@ make
 
 * Build on the ruby source directory.
 
-    ```
+    ```text
     ruby source directory:  C:\ruby
     build directory:        C:\ruby
     install directory:      C:\usr\local
     ```
 
-    ```
+    ```batch
     C:
     cd \ruby
     win32\configure --prefix=/usr/local
@@ -157,13 +157,13 @@ make
 
 * Build on the relative directory from the ruby source directory.
 
-    ```
+    ```text
     ruby source directory:  C:\ruby
     build directory:        C:\ruby\mswin32
     install directory:      C:\usr\local
     ```
 
-    ```
+    ```batch
     C:
     cd \ruby
     mkdir mswin32
@@ -176,13 +176,13 @@ make
 
 * Build on the different drive.
 
-    ```
+    ```text
     ruby source directory:  C:\src\ruby
     build directory:        D:\build\ruby
     install directory:      C:\usr\local
     ```
 
-    ```
+    ```batch
     D:
     cd D:\build\ruby
     C:\src\ruby\win32\configure --prefix=/usr/local
@@ -193,13 +193,13 @@ make
 
 * Build x64 version (requires native x64 VC++ compiler)
 
-    ```
+    ```text
     ruby source directory:  C:\ruby
     build directory:        C:\ruby
     install directory:      C:\usr\local
     ```
 
-    ```
+    ```batch
     C:
     cd \ruby
     win32\configure --prefix=/usr/local --target=x64-mswin64
@@ -224,7 +224,7 @@ Ruby uses [vcpkg](https://vcpkg.io/) to manage dependencies on mswin platform.
 
 You can update and install it under the build directory like:
 
-```
+```batch
 nmake update-vcpkg # Update baseline version of vcpkg
 nmake install-vcpkg # Install vcpkg from build directory
 ```
diff --git a/doc/yjit/yjit.md b/doc/yjit/yjit.md
index 284c21f323599f..0024c780b909d3 100644
--- a/doc/yjit/yjit.md
+++ b/doc/yjit/yjit.md
@@ -36,7 +36,7 @@ If you wish to learn more about the approach taken, here are some conference tal
 
 To cite YJIT in your publications, please cite the MPLR 2023 paper:
 
-```
+```BibTeX
 @inproceedings{yjit_mplr_2023,
 author = {Chevalier-Boisvert, Maxime and Kokubun, Takashi and Gibbs, Noah and Wu, Si Xing (Alan) and Patterson, Aaron and Issroff, Jemma},
 title = {Evaluating YJIT’s Performance in a Production Context: A Pragmatic Approach},
diff --git a/spec/ruby/CONTRIBUTING.md b/spec/ruby/CONTRIBUTING.md
index 5c3256948b87b2..366b484bada1c1 100644
--- a/spec/ruby/CONTRIBUTING.md
+++ b/spec/ruby/CONTRIBUTING.md
@@ -113,9 +113,9 @@ Also `have_constant`, `have_private_instance_method`, `have_singleton_method`, e
 }
 ```
 
-##### should_not raise_error
+##### `should_not raise_error`
 
-**To avoid!** Instead, use an expectation testing what the code in the lambda does.
+**Avoid this!** Instead, use an expectation testing what the code in the lambda does.
 If an exception is raised, it will fail the example anyway.
 
 ```ruby
diff --git a/tool/lrama/NEWS.md b/tool/lrama/NEWS.md
index e12c789d34b18f..a4a92f7a664464 100644
--- a/tool/lrama/NEWS.md
+++ b/tool/lrama/NEWS.md
@@ -6,7 +6,7 @@
 
 Allow to use aliased named references for actions of RHS in parameterizing rules.
 
-```
+```yacc
 %rule sum(X, Y): X[summand] '+' Y[addend] { $$ = $summand + $addend }
                ;
 ```
@@ -18,7 +18,7 @@ https://github.com/ruby/lrama/pull/410
 
 Allow to use named references for actions of RHS in parameterizing rules caller side.
 
-```
+```yacc
 opt_nl: '\n'?[nl] <str> { $$ = $nl; }
       ;
 ```
@@ -29,7 +29,7 @@ https://github.com/ruby/lrama/pull/414
 
 Allow to define parameterizing rules in the middle of the grammar.
 
-```
+```yacc
 %rule defined_option(X): /* empty */
                        | X
                        ;
@@ -117,7 +117,7 @@ https://github.com/ruby/lrama/pull/457
 
 Allow to specify tag on callee side of parameterizing rules.
 
-```
+```yacc
 %union {
     int i;
 }
@@ -130,7 +130,7 @@ Allow to specify tag on callee side of parameterizing rules.
 
 Allow to use named references for actions of RHS in parameterizing rules.
 
-```
+```yacc
 %rule option(number): /* empty */
                     | number { $$ = $number; }
                     ;
@@ -142,7 +142,7 @@ Allow to use named references for actions of RHS in parameterizing rules.
 
 Allow to nested parameterizing rules with tag.
 
-```
+```yacc
 %union {
     int i;
 }
@@ -199,7 +199,7 @@ expr -> '(', expr, ')' { $$ = $2; }
 Support inlining for rules.
 The `%inline` directive causes all references to symbols to be replaced with its definition.
 
-```
+```yacc
 %rule %inline op: PLUS { + }
                 | TIMES { * }
                 ;
@@ -213,7 +213,7 @@ expr : number { $$ = $1; }
 
 as same as
 
-```
+```yacc
 expr : number { $$ = $1; }
      | expr '+' expr { $$ = $1 + $3; }
      | expr '*' expr { $$ = $1 * $3; }
@@ -226,7 +226,7 @@ expr : number { $$ = $1; }
 
 User can specify the type of mid rule action by tag (`<bar>`) instead of specifying it with in an action.
 
-```
+```yacc
 primary: k_case expr_value terms?
            {
                $<val>$ = p->case_labels;
@@ -241,7 +241,7 @@ primary: k_case expr_value terms?
 
 can be written as
 
-```
+```yacc
 primary: k_case expr_value terms?
            {
                $$ = p->case_labels;
@@ -302,7 +302,7 @@ In general, these resources are freed by actions or after parsing.
 However if syntax error happens in parsing, these codes may not be executed.
 Codes associated to `%destructor` are executed when semantic value is popped from the stack by an error.
 
-```
+```yacc
 %token <val1> NUM
 %type <val2> expr2
 %type <val3> expr
@@ -350,7 +350,7 @@ Lrama provides these five callbacks. Registered functions are called when each e
 User also needs to access semantic value of their stack in grammar action. `$:n` provides the way to access to it. `$:n` is translated to the minus index from the top of the stack.
 For example
 
-```
+```yacc
 primary: k_if expr_value then compstmt if_tail k_end
           {
           /*% ripper: if!($:2, $:4, $:5) %*/
@@ -375,7 +375,7 @@ https://github.com/ruby/lrama/pull/344
 
 Allow to pass an instantiated rule to other parameterizing rules.
 
-```
+```yacc
 %rule constant(X) : X
                   ;
 
@@ -392,7 +392,7 @@ program         : option(constant(number)) // Nested rule
 
 Allow to use nested parameterizing rules when define parameterizing rules.
 
-```
+```yacc
 %rule option(x) : /* empty */
                 | X
                 ;
@@ -419,7 +419,7 @@ https://github.com/ruby/lrama/pull/337
 
 Allow to define parameterizing rule by `%rule` directive.
 
-```
+```yacc
 %rule pair(X, Y): X Y { $$ = $1 + $2; }
                 ;
 
@@ -442,7 +442,7 @@ https://github.com/ruby/lrama/pull/285
 Allow to specify type of rules by specifying tag, `<i>` in below example.
 Tag is post-modification style.
 
-```
+```yacc
 %union {
     int i;
 }
@@ -500,7 +500,7 @@ https://github.com/ruby/lrama/pull/204
 Parameterizing rules are template of rules.
 It's very common pattern to write "list" grammar rule like:
 
-```
+```yacc
 opt_args: /* none */
         | args
         ;
@@ -555,7 +555,7 @@ https://github.com/ruby/lrama/pull/44
 Instead of positional references like `$1` or `$$`,
 named references allow to access to symbol by name.
 
-```
+```yacc
 primary: k_class cpath superclass bodystmt k_end
            {
              $primary = new_class($cpath, $bodystmt, $superclass);
@@ -564,7 +564,7 @@ primary: k_class cpath superclass bodystmt k_end
 
 Alias name can be declared.
 
-```
+```yacc
 expr[result]: expr[ex-left] '+' expr[ex.right]
                 {
                   $result = $[ex-left] + $[ex.right];