Doug McIlroy writes: > If I were conscientious in writing about m4, I might choose > to use \(oq and \(cq to assure pretty typesetting.
That would break any sort of copy and paste in typeset output or even a UTF-8 terminal. The correct method would be to use \(aq (not \(aa) and \(ga for source code samples. The distinction between ` ' and left and right quotes seems to have taken hold in the mid 80s. Both Mac Roman (1984?) and Windows 2.0's CP1252 (1987?) separate the characters. I don't know when terminal fonts started making the switch but xterm's default font has looked that way as long as I can remember (which, granted, is not that long). > Still, this is a cautionary tale. What other sorts of > documents would suffer badly under this change? Other arcane character substitutions exist in troff. For example, ^ shows up as U+02C6 in typeset output, meaning literal '^' has to be escaped as \(ha. ~ shows up as U+02DC, and literal '~' must be escaped as \(ti. Many, many document authors are unaware of this distinction, which makes reading (or worse, searching) such incorrectly typeset documents as POSIX more than a little grating. -- Anthony J. Bentley
