Re: -S

COMMANDS
 - Followed by one of the command line option letters (see OPTIONS
 below), this will change the setting of that option and print a
 message describing the new setting. If a ^P (CONTROL-P) is
 entered immediately after the dash, the setting of the option
 is changed but no message is printed. If the option letter has
 a numeric value (such as -b or -h), or a string value (such as
 -P or -t), a new value may be entered after the option letter.
 If no new value is entered, a message describing the current
 setting is printed and nothing is changed.
 -- Like the - command, but takes a long option name (see OPTIONS
 below) rather than a single option letter. You must press
 ENTER or RETURN after typing the option name. A ^P immediately
 after the second dash suppresses printing of a message describ‐
 ing the new setting, as in the - command.
 -+ Followed by one of the command line option letters this will
 reset the option to its default setting and print a message
 describing the new setting. (The "-+X" command does the same
 thing as "-+X" on the command line.) This does not work for
 string-valued options.
 --+ Like the -+ command, but takes a long option name rather than a
 single option letter.
 -! Followed by one of the command line option letters, this will
 reset the option to the "opposite" of its default setting and
 print a message describing the new setting. This does not work
 for numeric or string-valued options.
 --! Like the -! command, but takes a long option name rather than a
 single option letter.
 _ (Underscore.) Followed by one of the command line option let‐
 ters, this will print a message describing the current setting
 of that option. The setting of the option is not changed.
 __ (Double underscore.) Like the _ (underscore) command, but
 takes a long option name rather than a single option letter.
 You must press ENTER or RETURN after typing the option name.
OPTIONS
 Command line options are described below. Most options may be changed
 while less is running, via the "-" command.