net-misc/openswan distribution comes with extensive documentation in ${S}/doc{,s} directories, none of which is installed by the ebuild (as of latest stable, ie. 2.4.15, although I eyeballed newer ebuilds and they don't seem to differ much in that respect); only documentation installed are HTML variants of the man pages, which is fairly useless or at best highly redundant -- that, and an index.html into documentation that is not installed, which is fairly irritating. I'd suggest adding IUSE=doc and then dodoc-ing appropriate files conditional on that USE flag.
Most files there are either development documentation or just remnants from the time when there was only one *swan (the dead FreeSWAN project). In openswan-2.6.23-r2 and openswan-2.4.15-r2 I've selected a few more files to be installed in the doc directory.
