Here's a proposed patch to make the Texinfo manual clearer about when sentences end.
2012-11-24 Paul Eggert <[email protected]> * doc/texinfo.txi (Not Ending a Sentence): Document the sentence-ending heuristic more clearly. This follows up on a request by Eli Zaretskii in <http://bugs.gnu.org/12973#14>. Index: doc/texinfo.txi =================================================================== RCS file: /sources/texinfo/texinfo/doc/texinfo.txi,v retrieving revision 1.493 diff -b -u -r1.493 texinfo.txi --- doc/texinfo.txi 24 Nov 2012 00:45:19 -0000 1.493 +++ doc/texinfo.txi 25 Nov 2012 01:55:34 -0000 @@ -10716,21 +10716,23 @@ @cindex Sentence non-ending punctuation @cindex Periods, inserting @cindex Spacing, in the middle of sentences -Depending on whether a period or exclamation point or question mark is -inside or at the end of a sentence, slightly less or more space is -inserted after a period in a typeset manual. Since it is not always -possible to determine automatically when a period ends a sentence, -special commands are needed in some circumstances. Usually, Texinfo -can guess how to handle periods, so you do not need to use the special -commands; you just enter a period as you would if you were using a -typewriter: put two spaces after the period, question mark, or -exclamation mark that ends a sentence. +Texinfo normally inserts slightly more space after the end of a +sentence in a typeset manual. When doing so, it uses a simple +heuristic: a sentence ends with any period or exclamation point or +question mark followed by optional closing punctuation, if the end of +sentence is followed by whitespace and is not preceded by a capital +letter. (Closing punctuation includes closing quotes, parentheses, +brackets, and braces---for example, this sentence ends after the +parenthesis at the end of this parenthetical remark.) Although this +heuristic lets Texinfo guess how to handle sentences so you typically +do not need to use special commands, it sometimes goes wrong and +special commands are needed. @findex <colon> @r{(suppress end-of-sentence space)} Use the @code{@@:}@: command after a period, question mark, exclamation mark, or colon that should not be followed by extra space. -For example, use @code{@@:}@: after periods that end abbreviations -which are not at the ends of sentences. +For example, use @code{@@:}@: after periods that end lower-case +abbreviations which are not at the ends of sentences. Also, when a parenthetical remark in the middle of a sentence (like this one!)@: ends with a period, exclamation point, or question mark,
