X

Most likely a proprietary Pro font. Ideas, NX and others have been notorious for them. Speaking of which... it looks very similar to ideas_new_iges1001, not that that likely helps you much, sorry.

here's my default font.
"default _annotation_font" "font.ndx"
i hope this will help

I am not sure of the name but I think I used somewhere. It might be a member in group of ISO fonts.