Hi!

-- >8 --
.Dd
.Dt STTY 1
.Os
.Sh DESCRIPTION
.TS
l .
_
=
\_
\=
.TE
-- >8 --
gets linted as
-- >8 --
mandoc: rep4.1:10:1: WARNING: undefined escape, printing literally: \=
-- >8 --
but correctly rendered as 
-- >8 --
STTY(1)                     General Commands Manual                    STTY(1)

DESCRIPTION
     ──
     ━━
     ─
     ━

Debian                         October 17, 2022                         Debian
-- >8 --
by mandoc 1.14.5-1 off Debian and CVS HEAD.

Best,
наб