An optional field to precise which application a script/plugin belongs to:
# api: streamtuner2
Which is a vanity tag foremost. You wouldn't normally mix scripts from different applications or languages and expect them to behave or work at all.
Nonetheless it makes sense for installation management, or filtering in plugin download repositories.
Additionally you still want to do some verification, such as
$meta.api ~= /^(|myapi|altname|python)$/
Usually you'd allow
# api: languagefor generic plugins (not bound to specific API).
And you might very well combine scripts from different APIs (in the same language, that is). For instance if one plugin implemented a stub API:
# provides: api:archnemesis
# api: NAMEis a shortcut for
# depends: api:NAME. See also depends