diff --git a/src/99-appendices/09-entities.md b/src/99-appendices/09-entities.md
index 2bbd081438..38ee57d17b 100644
--- a/src/99-appendices/09-entities.md
+++ b/src/99-appendices/09-entities.md
@@ -2,10 +2,15 @@
   This file is autogenerated based on the src/schema.  DO NOT EDIT DIRECTLY.
   Follow https://github.com/bids-standard/bids-specification/blob/master/CONTRIBUTING.md#updating-the-schema
 -->
-# Appendix IX: Entities
+# Appendix IV: Entity table
 
 This section compiles the entities (key-value pairs) described throughout this
-specification, and describes each.
+specification, and establishes a common order within a filename. 
+For example, if a file has an acquisition and reconstruction label, the
+acquisition entity must precede the reconstruction entity.
+REQUIRED and OPTIONAL entities for a given file type are denoted.
+Entity formats indicate whether the value is alphanumeric
+(`<label>`) or numeric (`<index>`).
 
 A general introduction to entities is given in the section on
 [file name structure](../02-common-principles.md#file-name-structure).
diff --git a/src/schema/datatypes/fmap.yaml b/src/schema/datatypes/fmap.yaml
index 98d0f6c45c..0391a6e0f1 100644
--- a/src/schema/datatypes/fmap.yaml
+++ b/src/schema/datatypes/fmap.yaml
@@ -31,3 +31,36 @@
     ce: optional
     dir: required
     run: optional
+# Third group
+- suffixes:
+    - TB1DAM
+  extensions:
+    - .nii.gz
+    - .nii
+    - .json
+  entities:
+    sub: required
+    ses: optional
+    run: optional
+    acq: optional
+    ce: optional
+    rec: optional
+    flip: required
+    part: optional
+# Fourth group
+- suffixes:
+    - TB1EPI
+  extensions:
+    - .nii.gz
+    - .nii
+    - .json
+  entities:
+    sub: required
+    ses: optional
+    run: optional
+    acq: optional
+    ce: optional
+    rec: optional
+    echo: required
+    flip: required
+    part: optional