It would be nice if there was a manpage that described ixl(4) in some detail without having to go to the source code.
We're working on it, but the first version probably won't describe ixl in very much detail.
ixl(4) is in CURRENT: http://www.freebsd.org/cgi/man.cgi?query=ixl&apropos=0&sektion=0&manpath=FreeBSD+11-current&arch=default&format=html
Yup, there's one in CURRENT, but it hasn't been backported to stable/10 yet..
A commit references this bug:
Date: Wed Jul 15 16:47:15 UTC 2015
New revision: 285603
MFC: r277218, r277219, r280572, r280573, r280574
Add manpages for the ixl and ixlv drivers.
Approved by: re (marius)
I merged the manpages to stable/10; thanks!