There seem to be a number of groff errors in the Korean tcpdump.1 page on various lines including the .IP command, such as line 440. .IP seems to take two arguments, a string and an optional numeric, and the first argument to .IP is not in quotes, so errors of the following form are given by groff: <standard input>:431: warning: numeric expression expected (got `)') <standard input>:440: warning: numeric expression expected (got `)') <standard input>:466: warning: numeric expression expected (got `)') These problems can be solved by putting quotes around the string arguments.
(In reply to benkasminbullock from comment #0) Please prepare a patch doing so. Though I cannot help but wonder if this port should not be removed instead. The port has no maintainer and the man pages have not been updated since 2002! They are probably very out of date. The description also says that it is an "early draft of korean online manual pages" which leads me to believe that even in 2002 they were incomplete.
A commit references this bug: Author: tobik Date: Sat Oct 20 13:06:26 UTC 2018 New revision: 482496 URL: https://svnweb.freebsd.org/changeset/ports/482496 Log: Deprecate korean/man-doc It is unmaintained, was last updated in 2002, some files have encoding errors [1], some appear to be machine translated [1], and it documents commands that have changed significantly since then with flags that no longer exist, new flags that are not documented, etc. PR: 212125 [1], 217826, 218176 Changes: head/korean/man-doc/Makefile