Q:

Approximating Fancy Punctuation

Is it ever okay (or acceptable in modern casual usage) to approximate an ellipse glyph '…' with three full-stops '...' or spaced full-stops '. . .'?
The textbooks say you shouldn't, but more and more people use this style nowadays. The differences are particularly noticeable in monospaced fonts:  …   ...   . . . 
Also, is it okay to approximate the em-dash '—' or en-dash '–' with hyphens?

A:

Unlike pure spelling and basic punctuation rules, the shape of punctuation marks and characters are governed only by style guide and personal practice. Some style guides even advise consistently using only three separate dots (never ellipses) and simple hyphens (never en dashes, em dashes, numeric dashes, or horizontal bars).
What level of typographic pedantry to apply in different levels of formality is basically up to you or your style guide. Personally, I always try to use as correct and exact punctuation marks as technically possible; but since that can sometimes, especially on the Internet, lead to font issues (the hair space set on either side of em dashes, for example, is missing from most non-standard web fonts, as is the horizontal bar) or other problems (introducing non-Latin characters in an SMS will reduce the number of available characters from 160 to 70, meaning you’ll quickly end up paying double if you’re sending longer texts), I often have to compromise.
If there are no technical hindrances, though, and you are able to type the required glyphs without too much difficulty, I can’t think of a good reason not to have your punctuation be as exact as possible.

