11.3.2 Not Ending a Sentence

When a period, exclamation point or question mark is at the end of a sentence, slightly more space is inserted after it in a typeset manual.

Usually, Texinfo can determine automatically when a period ends a sentence. However, special commands are needed in some circumstances. Use the @: command after a period, question mark, exclamation mark or colon that should not be followed by extra space. This is necessary in the following situations:

1. After a period that ends a lowercase abbreviation which is not at the end of a sentence.
2. When a parenthetical remark in the middle of a sentence (like this one!) ends with a period, exclamation point or question mark, @: should be used after the right parenthesis. Similarly for right brackets and right quotes (both single and double).

For example:

‘foo vs.@: bar (or?)@: baz’,

The first line below shows the output, and for comparison, the second line shows the spacing when the ‘@:’ commands were not used.

foo vs. bar (or?) baz
foo vs. bar (or?) baz

It may help you to remember what @: does by imagining that it stands for an invisible lower-case character that stops a word ending in a period.

A few Texinfo commands force normal interword spacing, so that you don’t have to insert @: where you otherwise would. These are the code-like highlighting commands, @var, @abbr, and @acronym (see Highlighting Commands are Useful). For example, in ‘@code{foo. bar}’ the period is not considered to be the end of a sentence, and no extra space is inserted.

@: has no effect on the HTML or DocBook output.