The notation_names function fills the array arr with an alphabetical list of notation names which are valid for the current document, returning the total number. The first name returned is stored at index 1. All previous elements in arr are discarded.

The doc argument specifies the identifier of the document tree to query. If omitted or 0, the current document is used.

If the exclude argument is 1, then the excludegraphicnotation hook is called to potentially exclude any notations from the array. If omitted or 0, all notations are included.