Last Call Review of draft-ietf-forces-model-extension-03
review-ietf-forces-model-extension-03-secdir-lc-yu-2014-09-04-00

I have reviewed this document as part of the security directorate's 
ongoing effort to review all IETF documents being processed by the 
IESG.  These comments were written primarily for the benefit of the 
security area directors.  Document editors and WG chairs should treat 
these comments just like any other last call comments.

Summary: ready with nits

I find the Security Considerations section of this document to be
reasonable.  I agree that there is negligible security impact from the
changes described in this document.

The capitalization is inconsistent for "DefaultValue" (in
typeDeclarationGroup) vs "defaultValue" (most other places).  I think
this poses no technical problem as written, but it could lead to
surprises if human-written XML is validated against the schema (assuming
I am correct in recalling that XML is case-sensitive).

Editorial:

I found it difficult to identify the before/after differences in the
schema fragments, especially when the quoted fragments are large.
Perhaps someone more familiar with XML schemas would not have this
difficulty.  I noticed that in some but not all of the schema fragments,
the "<!-- Extension -->" and <"!-- /Extension -->" comment annotations
are helpfully used to mark portions of the schema that have changed.
Notably, in Figures 2 and 4, these annotations are missing.  I would
prefer that changes be shown in a "unified diff" style, but I know that
is not idiomatic in the RFC format.

It would also be a good idea to describe the "<!-- Extension -->"
annotations in the text, to orient the reader to their use in the schema
fragments.

In Figure 4, the indentation seems incorrect and confusing.

In Figure 5, I found the inclusion of extension annotations in the
"original" excerpt from the schema to be confusing.  The preceding
paragraph does provide an explanation, but I wonder if it could be more
clear.  Figure 1 lacks this issue.

In case future documents make further revisions to the schema, perhaps
the extension comment annotations should include the RFC number of this
document so that a reader may distinguish which changes took place in
which documents.