The XQuery 3.1 standard defines only two annotations: %private and
%public. XQuery 3.0 Update defines only one:
%updating. It also states:
“Implementations may define further annotations, whose behaviour is
implementation-defined. For instance, if the eg prefix is bound
to a namespace associated with a particular implementation, it could define
an annotation like eg:sequential. If the namespace URI of an
annotation is not recognized by the implementation, then the annotation is
ignored. Implementations may also provide a way for users to define their
own annotations.”