the Tcl pages were usually all assigned to section l.  As this is unfortunate, it is now possible to put the pages in the correct section, and to assign a specific "extension" to them,  in
              this  case,  exit(3tcl).  Under normal operation, man will display exit(3) in preference to exit(3tcl).  To negotiate this situation and to avoid having to know which section the page you require resides in, it
              is now possible to give man a sub‐extension string indicating which package the page must belong to.  Using the above example, supplying the option -e tcl to man will restrict the search to pages having an  ex‐
              tension of *tcl.

       -i, --ignore-case
              Ignore case when searching for manual pages.  This is the default.

       -I, --match-case
              Search for manual pages case‐sensitively.

       --regex
              Show  all pages with any part of either their names or their descriptions matching each page argument as a regular expression, as with apropos(1).  Since there is usually no reasonable way to pick a "best" page
              when searching for a regular expression, this option implies -a.

       --wildcard
              Show all pages with any part of either their names or their descriptions matching each page argument using shell‐style wildcards, as with apropos(1) --wildcard.  The page argument must match the entire name  or
              description, or match on word boundaries in the description.  Since there is usually no reasonable way to pick a "best" page when searching for a wildcard, this option implies -a.

       --names-only
              If the --regex or --wildcard option is used, match only page names, not page descriptions, as with whatis(1).  Otherwise, no effect.

       -a, --all
              By default, man will exit after displaying the most suitable manual page it finds.  Using this option forces man to display all the manual pages with names that match the search criteria.

       -u, --update
              This option causes man to update its database caches of installed manual pages.  This is only needed in rare situations, and it is normally better to run mandb(8) instead.

       --no-subpages
              By  default,  man will try to interpret pairs of manual page names given on the command line as equivalent to a single manual page name containing a hyphen or an underscore.  This supports the common pattern of
              programs that implement a number of subcommands, allowing them to provide manual pages for each that can be accessed using similar syntax as would be used to invoke the subcommands themselves.  For example:

                $ man -aw git diff
                /usr/share/man/man1/git-diff.1.gz

              To disable this behaviour, use the --no-subpages option.

                $ man -aw --no-subpages git diff
                /usr/share/man/man1/git.1.gz
                /usr/share/man/man3/Git.3pm.gz
                /usr/share/man/man1/diff.1.gz

   Controlling formatted output
       -P pager, --pager=pager
              Specify which output pager to use.  By default, man uses pager, falling back to cat if pager is not found or is not executable.  This option overrides the $MANPAGER environment variable, which in turn overrides
              the $PAGER environment variable.  It is not used in conjunction with -f or -k.

              The value may be a simple command name or a command with arguments, and may use shell quoting (backslashes, single quotes, or double quotes).  It may not use pipes to connect  multiple  commands;  if  you  need
              that, use a wrapper script, which may take the file to display either as an argument or on standard input.

       -r prompt, --prompt=prompt
              If a recent version of less is used as the pager, man will attempt to set its prompt and some sensible options.  The default prompt looks like

               Manual page name(sec) line x