Because of the many disciplines involved in these areas of exploration and the rapidly developing theories associated with them, clarification of terms is vital. However, we do not intend to post final decisions on terminology but rather expose users to the variety of meanings.

For this reason, we have asked a number of experts to give definitions of various terms. People will be able to comment on these definitions. Comments will be of three forms:

Additions -- These are factual comments, such as references and historical notes.

Extensions -- These are more substantive comments.

Objections -- These are technical problems.