Re: [Last-Call] [Ext] Last Call: <draft-ietf-dnsop-dnssec-bcp-03.txt> (DNS Security Extensions (DNSSEC)) to Best Current Practice

[John C Klensin <[e-mail]>]

--On Friday, September 23, 2022 19:25 +0000 Amanda Baber
<[e-mail]> wrote:

> Hi,
> 
> IANA uses the term "registry group" to refer to top-level
> registries and "registry" to describe a set of registrations
> (as opposed to a set of sets). There are logistical reasons
> for this, but the use of the term "registry" in particular
> matches the usage in ICANN's MoU with the IETF (and our
> MoU-mandated performance reports).
> 
> I should add that we still use the term "sub-registry," but
> only to refer to, e.g., a registry of sub-TLVs for a TLV.

Amanda,

In the hope of getting something else on which I'm working [1]
right, some questions about the above: 

If I look at a protocol assignments page, e.g.,
https://www.iana.org/assignments/mail-parameters/mail-parameters.xhtml
is "MAIL Parameters" the "top-level registry" aka "registry
group", despite the fact that some of the registries on that
page are associated with different protocols (even if they are
somehow mail-related and, as we have discussed, there are
mail-related registries elsewhere)?

Also some of what I assume are called "registries" ("SMTP
Service Extensions", "SMTP Service Extension Parameters", "Mail
Transmission Types", etc.) are subsidiary to other ones there.
Does that make a difference? 

And, is "SMTP Service Extension Parameters" properly a
sub-registry of "SMTP Service Extensions"?  And, forgive my
ignorance, but what is a "TLV" in this context?

thanks,
   john



[1] draft-ietf-emailcore-rfc5321bis