screen manpage uses pretty extensive tbl table formatting, it has to be checked if a more semantic mandoc format fully supports it (or an alternative can be provided)

Screen comes packaged with and old format man file. It should be updated to something more modern.

For example, FreeBSD users are required to install Groff just to view this manpage. Almost all other manpages do not require this external program to view it.

This is what's currently needed just to view the screen manpage - it just seems excessive and unnecessary :

$ sudo synth status textproc/groff
Scanning existing packages.
These are the ports that would be built ([N]ew, [R]ebuild, [U]pgrade):
  N => devel/gperf
  N => print/libpaper
  N => dns/libidn
  N => graphics/jbig2dec
  N => graphics/poppler-data
  N => x11-fonts/fontconfig
  N => print/ghostscript9-agpl-base
  N => print/gsfonts
  N => print/psutils
  N => textproc/groff
Total packages that would be built: 10