Re: [urn] URN registration request for SCTE

Gary Hughes <> Tue, 27 August 2019 19:52 UTC

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From: Gary Hughes <>
Date: Tue, 27 Aug 2019 15:52:00 -0400
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Cc:, Dean Stoneback <>, Paul Woidke <>
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Subject: Re: [urn] URN registration request for SCTE
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Below is a revised version of the SCTE URN request form, hopefully
incorporating all of the comments and feedback.



IETF URN Registration for SCTE

Namespace Identifier:



The Society of Cable Telecommunications Engineers (SCTE) standards program
is an ANSI-accredited Standards Development Organization for the
development of technical specifications supporting cable
telecommunications.  SCTE standards work includes: data and telephony over
cable; application platform development; digital video; emergency alert
systems; network monitoring systems; cables, connectors and amplifiers;
construction and maintenance practices; energy management, and more.

Society of Cable Telecommunications Engineers
140 Philips Road, Exton, PA 19341-1318, USA

Designated contact:
 Role: Manager, Standards

Occasionally, SCTE specification efforts require identifiers in a managed
namespace so that they are unique and persistent.  To ensure that the
uniqueness is absolute, the registration of a specific Uniform Resource
Name (URN) Namespace Identifier (NID) for use by SCTE is being specified in
full conformance with the NID registration process specified in RFC8141

When SCTE specifications require the use of data models, a registered URN
Namespace which can be sub-divided according to our requirements is a key
construct to manage the definitions of those data models reliably with
persistence and uniqueness.

The use of URNs should also help specification authors to maintain
different versions of identifiers and dependencies between identifiers
across different versions of SCTE specifications if they so wish.

Specific URNs assigned in the ‘scte’ namespace are documented in the
defining SCTE standards.


Identifiers assigned in the ‘scte’ namespace will have the format

Identifier = “urn” “:” “scte” “:” NSS

The Namespace Specific String (NSS) of all URNs that use the "scte" NID
will have the following structure:


where the "{SCTEresource}" and “{ResourceSpecificString}” are US-ASCII
strings such that the URN conforms to syntax requirements of [RFC8141].

The grammar for SCTEresource and ResourceSpecificString is as follows:

       SCTEresource = unreserved  *( unreserved / pct-encoded / sub-delims
/ "@" / "/" )

       ResourceSpecificString = *( pchar / "/" )

This precludes the use of “:” in “SCTEresource”.

SCTE publishes information regarding the registered resources in the
corresponding SCTE standards. The “SCTEresource” may be used to identify
the SCTE standard or the project which defined the URN. The
“ResourceSpecificString” specifies the resource name and optionally the
edition (year) of the standard that first defined the URN.

For example:

Identifier of an XML namespace for audience-related metadata, defined in

Identifier used in an MPEG DASH EssentialProperty element to indicate that
a specified event stream is essential to the media presentation, first
defined in the 2015 edition of the SCTE DASH specifications

Identifier used in an MPEG DASH EventStream element to indicate that the
event message payloads are XML representations of SCTE 35 commands, as
first defined in the 2013 edition of ANSI/SCTE 35

Published SCTE standards are freely downloadable from the SCTE web site at:

All URNs that use the ‘scte’ NID are defined in SCTE standards.

SCTE will maintain a naming authority, the SCTE Assigned Names and Numbers
[SANN] specification, that will document the assignment of SCTE resource
classes and the specific registration values assigned for each resource
class along with references to the defining specification(s).  The SANN
 specification will be published on the SCTE Standards Program website (

The SANN specification will be updated as needed after the defining
specification(s) have been balloted and approved.

Security and Privacy:
There are no additional security considerations other than those normally
associated with the use and resolution of URNs in general, which are
described in [RFC8141].

SCTE standards are referenced by other SDOs and industry groups. Formally
registering the “scte” NID will help ensure that collisions do not occur.

The namespace is not listed with a resolution discovery system; this is not
applicable for this URN registration.

The SCTE Assigned Names and Numbers [SANN] specification will describe the
use of ‘scte’ namespace and assigned identifiers in the ‘scte’ namespace
and the defining SCTE standard. This will be available at

Details of URNs assigned in the ‘scte’ namespace are documented in the
defining SCTE standards.

Additional Information:
Participants involved in the development and usage of SCTE specifications
and cable industry deployments will benefit from the publication of this
namespace by providing consistent and reliable   names for the XML
namespaces, schema locations, and similar identifiers of physical data
models published within SCTE specifications.
The SCTE specifications are publicly available and are licensed to
manufacturers on a nondiscriminatory basis. SCTE will maintain the
corresponding specifications where the registered resources are referenced
or used.

Revision Information:
v2: revised to incorporate feedback
v1: This application is a revision and resubmission of

On Mon, Aug 26, 2019 at 12:52 PM Gary Hughes <> wrote:

> Dale, Juha, Lars,
> thank you for the feedback and suggestions. I will shortly post a revised
> version incorporating those changes.
> Regarding the examples, my intent was to show examples of syntax, but I
> will try to add some context without
> going too far into the weeds.
> Regarding "Is this meant to imply that SCTE URNs can only be assigned via
> standards"
> Yes. This ensures that URN assignments are subject to the same review and
> voting process as the standard. I
> will clarify that.
> regards,
> gary
> On Fri, Aug 23, 2019 at 6:30 AM <> wrote:
>> From me just a minor comment on Dale's comment:
>> On Donnerstag, 22. August 2019 um 03:39 Uhr "Dale R. Worley" <
>>> scripsit:
>> >     The use of URNs should also help specification authors to maintain
>> >     different versions of URNs and dependencies between URNs across
>> different
>> >     versions of SCTE specifications if they so wish.
>> >
>> > I'm not sure, but I think you want to replace "different versions of
>> > URNs and dependencies between URNs" with "different versions of
>> > identifiers and dependencies between ideentifiers" -- because of
>> > course, the use of URNs is helpful in maintaining different versions
>> > *of URNs*.  It's more interesting that use of URNs is helpful in
>> > maintaining different versions of *identifiers* generally.
>> I read this not so much as "different versions of identifiers" but as
>> "different versions of specifications [identified by identifiers/URNs]", so
>> clarification really seems needed here.
>> Apart from that I agree with Dale's and Juha's comments.
>> Best,
>> Lars