 During the first run of the show, the titles for seasons 2 and 4 changed as  character changes took place. In season 2, before Delenns new makeup was  revealed the "old" Delenn was shown; and for the first few episodes,  Claudia Christian was identified as "Lt. Commander. Susan Ivanova". After  she was promoted this was changed to "Commander Susan Ivanova". In the  fourth season, at first Jerry Doyle is identified as "Security Chief  Michael Garibaldi" while Jeff Conaway was billed as "Zack Allan". Halfway  through the season when Garibaldi resigns and Allan is promoted, the  credits change to "Michael Garibaldi" and "Security Chief Zack Allan".  However, the DVD/R1 release of Season 2 has all the credits showing the new  Delenn and "Lt. Commander Susan Ivanova"; and the Season 4 has all credits  showing "Security Chief Michael Garibaldi" and "Zack Allan".