I don't see any reason there shouldn't be standard CLASSes, especially if people want to move some of the current elements into CLASSes. Just as Ansi C and Posix specify namespace rules, there should be rules governing what CLASS names are reserved to authors, what names are reserved to vendors, and what names are reserved to the standard. It's the only way to manage an extensible namespace without having a registering organization.
For instance, if you say CLASS names beginning with '_' are reserved to the standard, and names beginning with alphanumeric characters [a-zA-Z0-9] are reserved to document authors, and names beginning with '@'are reserved to the organization whose Internet domain matches the prefix of the CLASS up to the next '@', you shouldn't have to worry about conflicts. I don't necessarily recommend those particular rules, but they illustrate the approach.
-- scott preece motorola/mcg urbana design center 1101 e. university, urbana, il 61801 phone: 217-384-8589 fax: 217-384-8550 internet mail: email@example.com