https://manpages.ubuntu.com/manpages/xenial/man3/XmFontListAppendEntry.3.html
Ubuntu Manpage: XmFontListAppendEntry - A font list function that appends an entry to a font list...
A font list function that appends an entry to a font list "XmFontListAppendEntry" "font list functions" "XmFontListAppendEntry"
font list