What format does man use

I checked what groff call is executed when I invoke man man (which uses the full width):

$ strace -o log -f -v -s 1024 -e trace=process man man

Looking for the groff call results in the following:

$ grep groff log | sed 's/\], \[.*//' 
28721 execve("/usr/bin/groff", ["groff", "-mtty-char", "-Tutf8", "-mandoc",
                                         "-rLL=171n", "-rLT=171n"

Now I resize my xterm:

$ strace -o log2 -f -v -s 1024 -e trace=process  man man
$ grep groff log2 | sed 's/\], \[.*//'
28852 execve("/usr/bin/groff", ["groff", "-mtty-char", "-Tutf8", "-mandoc",
                                         "-rLL=119n", "-rLT=119n"

Thus, I assume that the -rLL and -rLT arguments influence what terminal width is used by groff during compiling.

Solaris 10's default MANPATH is /usr/share/man. You can add values to it:

MANPATH="/usr/share/man:/opt/sfw/man"

See the man page for more information.

Solaris 11's default MANPATH is derived from PATH, so you wouldn't need to set the environment variable.