The playlist is stored in a file in the test's main directory. The playlist can be specific to a certain test session or it can be global for all sessions. If the playlist's file name has not been explicitly specified, a session specific playlist is searched for from file named 'playlist_sessionID' where sessionID is the session ID of the current session. For example, if the session's ID is 'ses3', the file named 'playlist_ses3' is looked for. If no session specific play list is not found, a file named 'playlist' is looked for (the global playlist). If it is not found, a playlist will not be used and items will be presented to the subject in the order the system reads them from the items list (but the presentation order may not be the same as the order of items in the items file).
The playlist is a text files that contains the list of item IDs to be played to a subject. Each line is contains one item ID. Comments can be added, the '#'-character marks the start of a comment which continues to the end of line. Empty lines are also allowed.
The following example explains the format of the file. There are four items listed in the playlist and they are to be played to the subject in the order item1, item3, item4, item2.
# # Order of items and which items are to be included in this test. # Not all items in items file have to be used. # item1 #and another comment item3# this is also a comment #yet another comment item4 item2