Unless you are a blogger or curious about how trackbacks work, this mailbag item will be of little interest.
The Commissar sends the following question:
I am confused about which URL to use for trackbacks. For the most part, I use the URL of the post itself. This works about half the time. For other blogs I have to use a Trackback URL. I put them in the URL’s to ping box. This URL, labeled Permalink is what I normally would use: (http://www.outsidethebeltway.com/archives/005167.html), but it didn’t work for OTB.
Next I tried the link labelled Trackbacks:
(http://www.outsidethebeltway.com/mt/mt-tb.cgi?__mode=view&entry_id=5167), but that one did not work either. But when I clicked open THAT URL, I found this one hiding inside: http://www.outsidethebeltway.com/mt/mt-tb.cgi/5167. And that one worked. For several other blogs, that same format xxxx/mt/mt-tb.cgi/NNNN seemed to work.
How do I tell, in advance, whether the post’s basic URL or the xxxx/mt/mt-tb.cgi/NNNN URL will work?
The URL that actually receives a trackback is the <$MTCGIPath$>/mt-tb.cgi/<$MTEntryID$> (Trackback URL). Since it’s sort of a pain to remember to use the trackback link, most blogging software has an autodiscover setting. In Movable Type (or TypePad) use your Weblog Config screen and make sure the Enable Trackback Autodiscovery box is checked. If that box is checked when you author a post MT will try to extract the Trackback URL’s for all the links in your post.
How does it do that? Look at the source code to one of my individual archive pages. In the rdf section the trackback:ping= line tells other programs where the corresponding Trackback URL is. For example:
dc:title=”Lewinsky Weighs In”
So the short answer is that if you have Trackback Autodiscovery enabled all you should need to do is have your link to other bloggers post in the body of your entry. With Trackback Autodiscovery enabled there is no need to put anything in the URL’s to ping box, Movable Type (and TypePad) handle the discovery for you. If for some reason the autodiscovery doesn’t work you have to put the Trackback URL (MTCGIPath/mt-tb.cgi/NNNN) in the URL’s to ping box manually.
Tip: Use the Preview button on a post, then go back to the edit screen and you should see the URL’s to ping box filled.