# | The hash symbol, #, is used as a wildcard to represent any number, so [FF#] would find [FF3] or [FF9987] but not [FF] or [FF 9] (because there's a space in it) or [FFhello]. |
* | The asterisk represents any string, so [FF* would find all of the above. * is used as the last character in the end-of-text symbol. It would find [FF anything at all up to the next <Enter>. |
^ | The ^ mark represents any single letter, so [FF^^] would find [FFZQ] but none of the others. |
? | The question mark represents any single character (including spaces, punctuation, letters), so [FF??] would find [FF 9] in the above examples, but none of the others. |
To represent a genuine #,^,? or *, put each one in double quotes, eg. "?" "#" "^" "*".
See also: Settings, Wildcards