-Automatically detects whether a syntax file is encoded in
-@var{encoding} or in a Unicode encoding such as UTF-8, UTF-16, or
-UTF-32. The @var{encoding} may be an IANA character set name or
-@code{Locale} (the default). Only ASCII compatible encodings can
-automatically be distinguished from UTF-8 (the most common locale
-encodings are all ASCII-compatible).
+Automatically detects whether a syntax file is encoded in an Unicode
+encoding such as UTF-8, UTF-16, or UTF-32. If it is not, then @pspp{}
+generally assumes that the file is encoded in @var{encoding} (an @acronym{IANA}
+character set name). However, if @var{encoding} is UTF-8, and the
+syntax file is not valid UTF-8, @pspp{} instead assumes that the file
+is encoded in @code{windows-1252}.
+
+For best results, @var{encoding} should be an @acronym{ASCII}-compatible
+encoding (the most common locale encodings are all @acronym{ASCII}-compatible),
+because encodings that are not @acronym{ASCII} compatible cannot be
+automatically distinguished from UTF-8.
+
+@item @code{Auto}
+@item @code{Auto,Locale}
+Automatic detection, as above, with the default encoding taken from
+the system locale or the setting on @subcmd{SET LOCALE}.