XMLTV ID
From MythTV Official Wiki
The XMLTV ID is required for mapping channels to channel listing services.
Zap2it
For Zap2it, you can find the ID using the following:
- Log in to your Zap2it account.
- Click the "Modify" button next to one of your lineups. This should bring you to a page allowing you to select and un-select channels.
- View the html source of the page (Firefox: top menu "View"->"Page Source").
- Search in the source for the callsign of the channel you are interested in.
- Above the callsign, you will see text like this: <LABEL FOR="000001145000000000300">. The XMLTVID is 5 digits long, ending at the 10th digit. In this example, the ID would be 11450.
Other listing services
If you know this, fill it in!