Annotated Source: Zork 3

Only the ADVENTURER has this property, and Zork 3 never uses it.

Only the SWORD has this property, and Zork 3 never uses it.

Set for objects which the player can BURN. (It might be a bad idea, but you can do it.)

This is different from FLAMEBIT, which indicates objects that are currently on fire. See also LIGHTBIT, objects which the player can TURN ON.

Set for objects which are on fire. Such objects normally also have ONBIT.

This is different from BURNBIT, which indicates objects that the player can BURN.

Set for objects which the player can sensibly TURN ON/OFF (e.g. the LAMP).

This is different from ONBIT, which indicates objects that are currently lit up. See also BURNBIT, objects which the player can BURN.

Set for glowing objects and naturally-illuminated rooms.

This is different from LIGHTBIT, which indicates objects that the player can TURN ON. See also FLAMEBIT, objects which are on fire.

Notionally this is for rooms which are solid ground. But Zork 3 doesn’t make use of this; every room has RLANDBIT, even ON-LAKE and IN-LAKE.

Not applied to real objects. RMUNGBIT is a hack used in grammar lines; it means the object is optional (but the preposition before it is required). This allows the parser to accept commands like LOOK AROUND.

Generally set for living beings, though not the ADVENTURER.

This is almost the same as VILLAIN, but some verbs use VILLAIN and some VICBIT, with no obvious pattern.

Interestingly, the MIRROR has VICBIT, possibly to support the idea of attacking and breaking it. This leads to a few buggy messages, though. (Try GIVE LAMP TO MIRROR, for example.)

Generally set for living beings, although they are generally not villainous in Zork 3. The SWORD reacts to this flag.

Compare VICBIT.

The ADVENTURER has the VILLAIN flag, which leads to a few buggy messages. Try HELLO ME or WAKE ME, for example. (The sword-glow avoids this, at least, since the ADVENTURER is also INVISIBLE.)