section 16 - Freshness details

[mcr]

> ** Section 16.  Can the thinking of this section be explained.  It
> seems out of place, and borders on being a solution.  The rest of this
> document talks about notional roles and architectures.  This text is
> focused on a particular nuance of message flow.  I'm wondering if we
> need it.  My thinking was to move this text to
> draft-birkholz-rats-epoch-markers.  As an aside, I did notice that
> draft-birkholz-rats-epoch-markers is using the amount of text on this
> topic in this document to motivate it's existence.