The df command currently allows only one of -l (local file systems only) or -t <fstype, ...> to be used.
This restriction is not necessary and has lead to PR 260921 being created. (https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=260921)
The patch allows both to be used simultaneously, with -l being an additional restriction if -t is used (i.e. -l -t nodevfs lists all local file systems except for devfs).