Trying to remember whether to use \1 or $1 depending on the program. Having to double-escape backslashes in Emacs. Regular expressions are an incredibly terse

Trying to remember whether to use \1 or $1 depending on the program. Having to double-escape backslashes in Emacs. Regular expressions are an incredibly terse way to express the goal... I deal with readability via concatenating well-named strings, each containing a portion of the larger regex.