When you choose Help > InDesign Help (or press F1), you may or may not be getting the most up-to-date help topic. In some cases, the web version of Help includes additional information not found in the in-product help. In other cases, users have left useful comments. The GREP search topic includes both additional information and commenting.
Feel free to leave comments in web help (also called LiveDocs Help). And drop me a note if you think any topic needs to be reworked.