The prefix of the exactly concerned tag handle will be matched by tag handle. There are three types of handle variants
- Primary Handle – Primary handle is indicated by single ! identifier. These are interpreted as local tags. The prefix associated with this handle is !.
- Seondary Handle – Secondary handle is indicated by double ! ! identifier. The prefix associated with this is tag:yaml.org, 2002:
- Named Handle – Named handle is surrounded by a non-empty name with ! character. A handle name cannot be used in tag shorthand until an explicit TAG has associated with some prefix.