Use of a dash in dimension labels

4'-6 1/2" 24"x36" opening
jojo

If I was *hand drafting*, the first would be: 4'-6½"
(You'll need a decent font/newsreader/platform to see the last char, decimal 189, which is a stacked fraction.) But since most software does poor to non-existant handling of stacked fractions down to at least 1/16" precision, we've adjusted how we express it digitally. We've added the space just to clarify the fraction. And at some point after the computer, some lackee started putting the dash in the wrong place which achieves your second example.
The second, hand drafted, would be: 24"×36"
And again, the middle char (decimal 215) is usually replaced these days with the English letter "x", although the proper character and meaning both imply "by". Not "x". I usually put space on either side of a *lower case* "x" (24" x 36") simply to distinguish the now confusing bottom-justified letter intermingled with numbers. But go back and look at drawings from the 1950's and you'll see the conventions from whence we came.
Now I'm not saying that the good ol' days were better, just that our software still has plenty of limitations that we work around. I always insist on decimal 1-128 and prohibit odd characters like degree marks, +/-, diameter, etc, simply because when you do an export to .dxf, .pdf, or even another font, you completely loose control. And I've been in architecture long enough now to prefer ugly over change orders. But it sure would be nice to have a single character to represent things like "square" (you know, the box with the vertical line through it) rather than having to either write it out or use an abbreviation that may or may not conflict with something else.

1384
Saves all the bother... (8-))

Thank you for the replies. I guess I can also see an answer to the 'dash' part of the question by looking at how Autocad does it.. ;-) Steve