The Allow trackback / pingback option controls the usability of trackbacks and pingbacks. When this option is enabled, other blogs may post trackback (or pingback) entries to your blog. Trackback and pingback entries are always moderated by default so they will not be seen by anyone else until you approve them. If you are allowed to edit entries, you may turn this option on and off after an entry has been published.
You may set the default for this choice in the Blog Control Panel.
This option will not appear if trackbacks / pingbacks have been disabled by the administrator.