To associate an SVN commit with an OpenG Bug Tracker or OpenG Feature Request Tracker case number (TrackerID) enter the TrackerID into the "TrackerID:" field in the upper-right corner of the TortoiseSVN commit dialog, as shown below.

When an SVN commit is associated with a TrackerID, you can then view this information in the Log Message, as shown below. Clicking on the hyperlink in the Log Message will take you to the cases history web page on the OpenG tracker website.