Current draft of Transfer.Put says:

This operation will replace the entire XML representation of the resource. Any optional values (elements or attributes) not specified in the Put request message will be set to a resource-specific default value. 

For default Put this is true - meaning it replaces the entire XML representation.
However, when using an extension spec, like ws-fragment, its possible that
only part of the resource will be updated.  The case that I'm most worried
about is one where each property of a resource has a timestamp associated with
it.  If they use ws-frag then, per the Transfer spec, all of the timestamps
for all properties would need to be touched - which isn't really what's
expected.

Proposal:
Change the above text slightly to allow for extensions to define how they
modify the resource:

Unless otherwise specified by an extension, this operation will replace
the entire XML representation of the resource, and any optional values
(elements or attributes) not specified in the Put request message will be
set to a resource-specific default value.