The lmc(4) driver supports hardware for a number of legacy interfaces, including EIA612/613, T1/E1, T3, etc. The driver's license is ambiguous and attempts to contact the author failed. I would like to remove this driver from 12.0, and have a deprecation notice in review D15182 [1]; I would appreciate hearing from anyone who is currently using lmc(4) in case it is still providing some value. [1] https://reviews.freebsd.org/D15182