If the variable @code{colon-double-space} is non-@code{nil}, the
fill commands put two spaces after a colon.
+@vindex sentence-end-without-period
+The variable @code{sentence-end-without-period} can be set
+non-@code{nil} to indicate that a sentence will end without a period.
+For example, a sentence in Thai text ends with double space but without
+a period.
+
@node Fill Prefix
@subsection The Fill Prefix