README comment on mul

README.md

@@ -325,9 +325,9 @@ Our tags are of form `xxx_Yyyy_ZZ` where
 Notes:
 * Region is preserved when available and left blank when unavailable
 * Script `Yyyy` is forcibly suppressed in obvious cases. E.g. `eng` is written using `Latn` script, writing `eng-Latn` is just awkward to read as `Latn` is default we suppress `Latn` script for English. On the other hand a language like `Kannada` is written using `Knda` script (`kan-Knda` -> `kan`), but occasionally written using `Latn` script, so `kan-Latn` is not suppressed. 
-* The information about whats default script is obtained from IANA language code registry 
+* The information about what is default script is obtained from IANA language code registry 
+* Language code `mul` stands for _multiple languages, and is used as a placeholder for multilingual datasets (See `mul-eng` to represent many-to-English dataset recipes in [(mtdata/recipe/recipes.yml](mtdata/recipe/recipes.yml))
 
-  
 #### Example:
 To inspect parsing/mapping, use `python -m mtdata.iso.bcp47 <args>`