Other negative values can have bad effects and won't be allowed
anymore.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
<listitem>
<para>
The number of days warning given before a password expires. A zero
- means warning is given only upon the day of expiration, a negative
- value means no warning is given. If not specified, no warning will
+ means warning is given only upon the day of expiration, a value of
+ -1 means no warning is given. If not specified, no warning will
be provided.
</para>
</listitem>