1) Formal language
Found on
https://www.crosswordclues.com/clue/metacharacter
A metacharacter is a character that has a special meaning (instead of a literal meaning) to a computer program, such as a shell interpreter or a regular expression engine. In POSIX extended regular expressions, there are 14 metacharacters that must be preceded by a backslash `` in order to drop their special meaning and be treated literally insi.....
Found on
http://en.wikipedia.org/wiki/Metacharacter
No exact match found.
