groff: Sentences
5.1.3 Sentences
---------------
Although it is often debated, some typesetting rules say there should be
different amounts of space after various punctuation marks. For
example, the 'Chicago typesetting manual' says that a period at the end
of a sentence should have twice as much space following it as would a
comma or a period as part of an abbreviation.
'gtroff' does this by flagging certain characters (normally '!', '?',
and '.') as "end-of-sentence" characters. When 'gtroff' encounters one
of these characters at the end of a line, it appends a normal space
followed by a "sentence space" in the formatted output. (This justifies
one of the conventions mentioned in ⇒Input Conventions.)
In addition, the following characters and symbols are treated
transparently while handling end-of-sentence characters: '"', ''', ')',
']', '*', '\[dg]', '\[rq]', and '\[cq]'.
See the 'cflags' request in ⇒Using Symbols, for more details.
To prevent the insertion of extra space after an end-of-sentence
character (at the end of a line), append '\&'.