back when Glock had like 6 or 7 models. Now days evidently not so much. I see the letters "SF" and the words "short frame" used when describing different Glocks, yet when I visit Glocks website I find no mention of either terms. So fill an old guy in, what gives with the SF or short framed Glocks people keep referring to? Thanks in advance, Gary FWIW I have owned two model 20s two model 21s a 22 a 23 and a model 24(non-comped)in the past. I think I am most interested in a model 29 at this point.