As of v11 (Eden), XBMC now has support for offline media stub files. These are files that represent a media outside of the online digital infrastructure and allow XBMC's library to catalog your "offline" media collection, as well as ask for the media when selected for playback.
By default these files have a .disc extension (modifiable via advancedsettings.xml). In cooperation with Confluence Skin's (and possibly others) feature to search for words like DVD, Bluray, and HDDVD in the file name it is possible to create a disc stub file that will show correct media flags in the skin. For example, if you have Finding Nemo on DVD, you could create an empty file called: "Finding Nemo (2003).dvd.disc" and add it to your library. In the XBMC library this file will show up with the DVD media flag in the Confluence Skin and when selected you will be prompted to insert the Finding Nemo DVD.
You can also add media source flags (if the skin you are using supports them) to indicate the type of media (DVD, BR, VHS, etc) in the GUI. For more info on this, see Media flags#Media source.
You can also add a custom message to be displayed when attempting to play a Disc Stub file. This is accomplished by treating the disc stub file as an xml file with the following layout:
<discstub> <message>Message to be displayed</message> </discstub>
The message will be displayed on the second line of the dialog box that asks you to insert a disc when selecting a disc stub file for playback. This added feature allows users who use a numbered library for their disc media to also take advantage of this new Disc Stub file support in XBMC.