An item which is not super obvious when using expressions is that the “\” character is actually an escape character. This is standard with strings, but for users who aren’t familiar with that convention it is not intuitive.
This mainly shows up with Regular expressions, since all backslashes in the expression have to be doubled for the expression to run correctly. For example, see below:
It would be nice to have escape backslashes given a different color compared to normal text, to make it clear that this is not a normal character.
EDIT: I did not catch this originally but the \ character is ALSO an escape character in the community comments editor, and was missing before