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website/docs/ref/catalog-formats.md

@@ -210,6 +210,22 @@ With this format, plural messages are exported in the following ways, depending
 
   Note how `msgid` and `msgid_plural` were extracted from the original message.
 
+
+- Message **with a custom comment prefix**.
+
+  Some TMS might modify the ICU comment by attempting to split lines to be 80 characters or less,
+  or have trouble reading lingui comments because of the `js-lingui:` prefix. To change the prefix,
+  set `customCtxPrefix` to modify the prefix for ICU comments.
+
+  ```po
+  # with default prefix
+  #. js-
+  #. lingui:icu=%7BanotherCount%2C+plural%2C+one+%7BSingular+case%7D+other+%7BCase+number+%7BanotherCount%7D%7D%7D&pluralize_on=anotherCount
+
+  # customCtxPrefix = jsi18n:
+  #. jsi18n:icu=%7BanotherCount%2C+plural%2C+one+%7BSingular+case%7D+other+%7BCase+number+%7BanotherCount%7D%7D%7D&pluralize_on=anotherCount
+  ```
+
 ### Limitations {#po-gettext-limitations}
 
 This format comes with several caveats and should only be used when using ICU plurals in PO files is not an option: