When the player refers to an object during the course of the game, they may use as many or as few of its names as required to uniquely identify it. For example, consider the following three objects:
object ball_1: ball
object ball_2: small red ball
object ball_3: big red ball
Presuming all these objects were in the current location, if the player referred to ball, then ball_1 would be selected. This is because the JACL interpreter divides the number of names an object has by the number of names supplied to come up with a best match. Although all three objects have the name ball, ball_1 matches 100% while ball_2 and ball_3 only match 33%. If the player referred to red ball, then ball_1 would automatically be excluded, as it does not have the name red. On the other hand, both ball_2 and ball_3 have the names red ball, and both would match 66%. In this case a message displays stating that the reference was ambiguous. If the player referred to big, then ball_3 would automatically be selected as neither of the other two objects have the name big at all.
It is important to be aware of the number of names that you give each object, and how they relate to each other. It is generally best to have two similar objects have the same number of names, although in some cases you may wish to nominate one to be the default by giving it less names.
For example, in one of my own games, The Unholy Grail, there are two objects: beige agar and brown agar. To avoid problems when looking up agar in the encyclopedia, a third object named simply agar was added. This object stays permanently in limbo and therefore does not affect any physical manipulation of the two real agar objects. It does, however, get selected when using commands such as ask_about that except objects that are *anywhere.