Lintial (tool to check debian packages) says:
===This manual page seems to contain a hyphen where a minus sign was
intended. By default, "-" chars are interpreted as hyphens (U+2010) by
groff, not as minus signs (U+002D). Since options to programs use minus
signs (U+002D), this means for example in UTF-8 locales that you cannot
cut and paste options, nor search for them easily. The Debian groff
package currently forces "-" to be interpreted as a minus sign due to
the number of manual pages with this problem, but this is a
Debian-specific modification and hopefully eventually can be removed.
"-" must be escaped ("\-") to be interpreted as minus. If
you really
intend a hyphen (normally you don''t), write it as "\(hy" to
emphasise
that fact. See groff(7) and especially groff_char(7) for details, and
also the thread starting with
http://lists.debian.org/debian-devel/2003/debian-devel-200303/msg01481.html
===