I'm a big fan of using identifiers such as 'list, 'string, 'fn (isn't a problem in CL, but is one in Arc), 'array, 'char, etc. Often a general name is the most concise and appropriate name to use.
I think that since Arc is supposed to be designed towards flexibility and usability for the programmer, it should have few restrictions, and a common namespace is such a restriction.
However, my opinion on this could change as I explore Arc over the next few weeks.
