-There are two variants of command syntax, @i{viz}: @dfn{batch} mode and
-@dfn{interactive} mode.
-Batch mode is the default when reading commands from a file.
-Interactive mode is the default when commands are typed at a prompt
-by a user.
-Certain commands, such as @cmd{INSERT} (@pxref{INSERT}), may explicitly
-change the syntax mode.
-
-In batch mode, any line that contains a non-space character
-in the leftmost column begins a new command.
-Thus, each command consists of a flush-left line followed by any
-number of lines indented from the left margin.
-In this mode, a plus or minus sign (@samp{+}, @samp{@minus{}}) as the
-first character in a line is ignored and causes that line to begin a
-new command, which allows for visual indentation of a command without
-that command being considered part of the previous command.
-The period terminating the end of a command is optional but recommended.
-
-In interactive mode, each command must be terminated with a period
-or by a blank line.
-The use of @samp{+} and @samp{@minus{}} as continuation characters is not
-permitted.
+There are three variants of command syntax, which vary only in how
+they detect the end of one command and the start of the next.
+
+In @dfn{interactive mode}, which is the default for syntax typed at a
+command prompt, a period as the last non-blank character on a line
+ends a command. A blank line also ends a command.
+
+In @dfn{batch mode}, an end-of-line period or a blank line also ends a
+command. Additionally, it treats any line that has a non-blank
+character in the leftmost column as beginning a new command. Thus, in
+batch mode the second and subsequent lines in a command must be
+indented.
+
+Regardless of the syntax mode, a plus sign, minus sign, or period in
+the leftmost column of a line is ignored and causes that line to begin
+a new command. This is most useful in batch mode, in which the first
+line of a new command could not otherwise be indented, but it is
+accepted regardless of syntax mode.
+
+The default mode for reading commands from a file is @dfn{auto mode}.
+It is the same as batch mode, except that a line with a non-blank in
+the leftmost column only starts a new command if that line begins with
+the name of a @pspp{} command. This correctly interprets most valid @pspp{}
+syntax files regardless of the syntax mode for which they are
+intended.
+
+The @option{--interactive} (or @option{-i}) or @option{--batch} (or
+@option{-b}) options set the syntax mode for files listed on the @pspp{}
+command line. @xref{Main Options}, for more details.