The class of an XG line type defines its function. Each type belongs to a single class and thus performs only one function, like initiating a plane move or changing the type of a sector. The Class property of the Line Type definition selects the class to use.

Definitions of the available line classes are listed below. These flags are defined in Doomsday's standard flags.ded.

Flag { ID = "ltc_none"; }
Flag { ID = "ltc_chain_sequence"; Value = 0x1; }
Flag { ID = "ltc_plane_move"; Value = 0x2; }
Flag { ID = "ltc_build_stairs"; Value = 0x3; }
Flag { ID = "ltc_damage"; Value = 0x4; }
Flag { ID = "ltc_power"; Value = 0x5; }
Flag { ID = "ltc_line_type"; Value = 0x6; }
Flag { ID = "ltc_sector_type"; Value = 0x7; }
Flag { ID = "ltc_sector_light"; Value = 0x8; }
Flag { ID = "ltc_activate"; Value = 0x9; }
Flag { ID = "ltc_key"; Value = 0xA; }
Flag { ID = "ltc_music"; Value = 0xB; }
Flag { ID = "ltc_sound"; Value = 0x14; }
Flag { ID = "ltc_line_count"; Value = 0xC; }
Flag { ID = "ltc_end_level"; Value = 0xD; }
Flag { ID = "ltc_leave_map"; Value = 0xD; } # Alias for end_level
Flag { ID = "ltc_disable_if_active"; Value = 0xE; }
Flag { ID = "ltc_enable_if_active"; Value = 0xF; }
Flag { ID = "ltc_explode"; Value = 0x10; }
Flag { ID = "ltc_plane_texture"; Value = 0x11; }
Flag { ID = "ltc_plane_material"; Value = 0x11; } # Alias for plane_texture
Flag { ID = "ltc_wall_texture"; Value = 0x12; }
Flag { ID = "ltc_wall_material"; Value = 0x12; } # Alias for wall_texture
Flag { ID = "ltc_command"; Value = 0x13; }