CategoryTrackbackCount
The number of published TrackBack pings for the category in context.
Use the mt:Pings loop to list the pings for a category.
Example
Display the count of trackbacks for the category in context and the trackback link:
<mt:CategoryIfAllowPings>
<!-- do something -->
<$mt:CategoryTrackbackCount$>
<$mt:CategoryTrackbackLink$>
</mt:CategoryIfAllowPings>