metacharacter

This term is primarily used in the technical registers of computer science, specifically within the context of regular expressions and shell scripting. It describes a symbol that triggers a specific functional operation rather than being treated as a literal piece of text. For example, while a period usually ends a sentence, as a metacharacter in a regex pattern, it matches any single character.

Users should distinguish between the metacharacter itself and the literal character it represents. To treat a metacharacter as a literal character, one must typically use an escape sequence, such as a backslash, to neutralize its special functional power.