The file(1) and magic(5) man pages' groff source makes references to undefined
strings: \*[Am], \*[Lt], and \*[Gt].  These are intended to display as &, <, and
> respectively.  These characters are critical in magic(5).

Additionally, in the synopsis of file(1), there is a line:
  \*[Am]...
that really should be:
  \&...
(preventing the elipsis from being interpreted as a command).

file(1) is maintained by Cristos Zoulas and is distributed from
<ftp://ftp.astron.com/pub/file/file-X.YY.tar.gz>.  There are currently two
versions there: 3.41 and 4.04.  3.41 still has the problems but 4.04 does not.

The following definitions, added near the top of each file, would solve the
first problem:
.ds Am &
.ds Lt <
.ds Gt >