what do mean by standard, and extensible?

An issue we've been dealing with in the metadata group, Rick Jelliffe  
is dinging us a bit on some OpenFormula related wiki content:

<http://www.oreillynet.com/xml/blog/2006/09/ 
freaked_out_by_odfs_definition.html>

For metadata, I actually thing Rick is a bit off-base that there need  
be such a gulf between the two -- one can standardize the model without  
standardizing the specific markup; standardize some of the markup/terms  
without worrying about standardizing all of it -- but I think it's  
worth clarifying the issue he raises as we move forward.

When do we standardize something, and when do we leave a structure in  
place that allows extension to happen without the involvement of the  
TC?

When, for example, should a formula extension be submitted for  
inclusion in the spec, and when not? Is extension here just a mechanism  
to fill the time gap between implementation and TC standardization?

For metadata, I think the standards of inclusion would likely be  
different, but we'd still want some statement on this.

Bruce