Chronology of what was authored in the year, 1999
Being a participant with a verifiable identity has advantages as much as operating anonymously permits privacy. Support for both is provided by the ability to alternate between two modes seamlessly.
The default mode for anonymity requires zero credentials. When credentials are required, the participant must then leave or present the proper level.
The basic modes are anonymous versus identity. Each contain multiple levels with progressively more private information.
Additional levels may be introduced between those presented here. This is merely a starting point.