NAME
        FilterTagItems -- remove selected items from a tag list. (V36)

   SYNOPSIS
        numValid = FilterTagItems(tagList,filterArray,logic);
        D0                        A0      A1          D0

        ULONG FilterTagItems(struct tagitem *,tag *,ulong);

   FUNCTION
        Removes tag items from a tag list (by changing ti_Tag to
        TAG_IGNORE) depending on whether its ti_Tag value is
        found in an array of tag values.

        If the 'logic' parameter is TAGFILTER_AND, then all items
        not appearing in 'tagArray' are excluded from 'tagList'.

        If 'logic' is TAGFILTER_NOT, then items not found in 'tagArray'
        are preserved, and the ones in the array are cast out.

   INPUTS
        tagList - input list of tag items which is to be filtered by having
                  selected items changed to TAG_IGNORE.
        filterArray - an array of tag values, terminated by TAG_DONE, as
                      specified in the documentation for taginarray().
        logic - specification whether items in 'tagArray' are to be included
                or excluded in the filtered result.

   RESULTS
        numValid - number of valid items left in resulting filtered list.

   SEE ALSO
        <utility/tagitem.h>, taginarray()