See
http://dmoz.org/guidelines/site-specific.html#multiple for more details regarding multiple listings of one site.
"Sites that are relevant to a subject category and a specific local geographic area. Many sites can be listed once in a topical branch of the ODP, and once in the Regional category."
Besides the general guidelines located at
http://dmoz.org/guidelines/ it is _always_ a good idea to look at the submission guidelines (i.e., category descriptions and/or FAQs) of the potential category being submitted to. If none exist, take a peak at the parent category and its description/submission guidelines.
> Some sites should only be listed in topical. <img src="/images/icons/wink.gif" alt="" />
> Some sites should only be listed in Regional. <img src="/images/icons/ooo.gif" alt="" />
> Some sites may be listed in topical and Regional. <img src="/images/icons/cool.gif" alt="" />
> Some sites should not be listed. <img src="/images/icons/frown.gif" alt="" />
> Some sites are listed, but should not be listed. <img src="/images/icons/blush.gif" alt="" /> The _volunteer_ editing community and the public should and do work together to reduce these numbers.
> Some sites are not listed, but should be listed. <img src="/images/icons/laugh.gif" alt="" /> The _volunteer_ editing community and the public should and do work together to increase these numbers.