AUTOTEXT GUIDEThis suggest to me that if you have a hidden string Parameter you could predefine it with <CURRENTISSUEID> and then reference that parameter in your scripts. It's a while since I did any serious GDL so it's just a suggestion that I haven't actually tried.
It’s not part of GDL itself. ARCHICAD will substitute all references to autotext fields in whatever GDL output it finds them. For example, if you write <PROJECTSTATUS> in the parameter string of a text2 command, ARCHICAD will nicely replace it with the actual value. All this is invisible to GDL – consequently the size and other attributes of the text are not measurable.