the mount(8) man page covers not only the mount command, but also the
various file system options that come from the kernel.  it seems like
the communities have settled on the man-pages project for holding all
the userland-facing documentation, it has good practices for tracking
features across versions, and updating it is a lot easier/safer (than
util-linux) and up-to-date on the web (via man7.org).  while looking
up some proc/ramfs options, i noticed util-linux was out of date by
over 6 years :/.

imo, it seems like we should move all kernel-specific documentation
out of the util-linux project and into man-pages.  obviously all the
mount command line options and such should remain.

specifically i'm looking at "FILESYSTEM-SPECIFIC MOUNT OPTIONS":
http://man7.org/linux/man-pages/man8/mount.8.html#FILESYSTEM-SPECIFIC_MOUNT_OPTIONS

we probably want to leave "FILESYSTEM-INDEPENDENT MOUNT OPTIONS"
in util-linux since those are all parsed by util-linux's mount
and turned into the MS_xxx bits.

thoughts ?  mount(2) doesn't seem like the best place, but these
are the fields that go in the "data" string to that syscall.
-mike