The "-l" option doesn't seem to be documented in the "emerge" man page. Reproducible: Always Steps to Reproduce:
synced up `emerge --help` with the man page ... as you may see below, a lot more was missing ;) http://cvs.gentoo.org/cgi-bin/viewcvs.cgi/gentoo-src/portage/man/emerge.1.diff?r1=1.37&r2=1.38