15.3.5.9 Imported syntactic bindings: fluid syntaxes

A syntactic binding representing an imported keyword binding associated to a fluid syntax has descriptor with format:

($fluid . ?fluid-label)

where ?fluid-label is a further label gensym used to redefine the keyword binding; How fluid syntaxes work.

Syntactic bindings of this type are established by uses of the syntax define-fluid-syntax.