Depending on whether a period or exclamation point or question mark is inside or at the end of a sentence, less or more space is inserted after a period in a typeset manual. Since it is not always possible to determine when a period ends a sentence and when it is used in an abbreviation, 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, which means you put two spaces after the period, question mark, or exclamation mark that ends a sentence.
Use the @: command after a period, question mark,
exclamation mark, or colon that should not be followed by extra space.
For example, use @: after periods that end abbreviations
which are not at the ends of sentences.
For example,
The s.o.p.@: has three parts ...
The s.o.p. has three parts ...
The s.o.p. has three parts ...
The s.o.p. has three parts ...
(Incidentally, s.o.p. is an abbreviation for "Standard Operating
Procedure".)
@: has no effect on the Info output. Do not put braces after
@:.