Might the first element reference be for specialized exporting?
Specialised Import Lists
If the first entry in an import list begins with !, : or / then the list is treated as a series of specifications which either add to or delete from the list of names to import. They are processed left to right. Specifications are in the form:
[!]name This name only
[!]:DEFAULT All names in @EXPORT
[!]:tag All names in $EXPORT_TAGS{tag} anonymous list
[!]/pattern/ All names in @EXPORT and @EXPORT_OK which match A leading ! indicates that matching names should be deleted from the list of names to import. If the first specification is a deletion it is