EVENT LOGO
Apparently this has something do to with the 3D Realms screen, the title screen (with logos), the main menu background MIDI, and the opening nuke symbol (LOGO.ANM).
enum logoflags { LOGO_FLAG_ENABLED = 1, LOGO_FLAG_PLAYANIM = 2, LOGO_FLAG_PLAYMUSIC = 4, LOGO_FLAG_3DRSCREEN = 8, LOGO_FLAG_TITLESCREEN = 16, LOGO_FLAG_DUKENUKEM = 32, LOGO_FLAG_THREEDEE = 64, LOGO_FLAG_PLUTOPAKSPRITE = 128 };