Template:cheatsheet-key
Key
Based on Perl's standard quantifiers:
| bold {1} | MUST be present exactly once |
| italic* | OPTIONAL, and MAY occur more than once |
| + | MUST occur, and MAY occur more than once |
| ? | OPTIONAL, but MUST NOT occur more than once |
| [square brackets] | list of common values |
| (parentheses) | data format |
| # | comment |
| ! | awaiting documentation |