Question about default for @format when linking to file.htm

[Robert D Anderson <robander@us.ibm.com>]

Hi,

I see a draft comment in the write up for proposal 13107 (assume a default value for @format based on the extension of the linked resource. Bob's comment states:
This description needs to specify that a ".htm" extension MUST imply format value "html".

That's a slight change from the approved proposal, so I wanted to send to the TC before making that change.
1. Is that correct - an extension of "htm" means format="html" (rather than format="htm")?
2. Is this something that we want to list as MUST with a reference to the RFC terminology?

Thanks -

Robert D Anderson
IBM Authoring Tools Development
Chief Architect, DITA Open Toolkit (http://dita-ot.sourceforge.net/)