Labels are always Fixed. In ArchiCAD terms that means they will always remain the same size, no matter what the scale is. If you're using the imperial units, it will be a measurement in Points (Pts) where there are 72 points in an inch. So a 1/8" piece of text will be 9 Pt high. Metric uses mm.
It doesn't matter what the scale of the drawing is, the label text will always be the same. New users or otherCAD users are often confused by this thinking that their text has suddenly grown or shrunk, when it hasn't. It always stayed the same size, it's just that the model appears to have grown or shrunk.
Once you get the hang of it, you realize just how important it is to get your anchor points and justification right, so your text doesn't jump all over the joint whenever you change scale.
Text can be set to Scaled, but labels are always set to Fixed. So are Dimensions.
Cheers,
Link.
I misinterpreted what you wrote...I guess I didn't have enough coffee this morning.