[Ietf-calsify] ADD is really optional --?

[Lisa Dusseault]

I'm doing AD Review of iTIP and the way I read specs like this by  
default is that if there are a bunch of methods that can be sent  
around between agents, all of them must be supported.

However, for the ADD method, iTIP specifies a way for a receiving  
client not to really support it -- return a REQUEST-STATUS of 3.14  
followed by a REFRESH request.

Is ADD routinely supported by iTIP implementations or is this  
exception used in practice?

Lisa