What is the OR operator in emacs regexps?

Question

The manual says to use \'\\|\', as in a\\|b matches a or b. But when I use it with regexp builder or align-regexp e.g. with, \"True\\|False\", it doesn\'t recognize \"True\" or

Answer 1

For further details, see the discussion of '\' and strings in the elisp manual section 34.3.1.1 "Special Characters in Regular Expressions"

M-: (info "(elisp) Regexp Special") RET