The Library

By downloading, copying, distributing, and/or referencing the documents contained herein, you hereby agree as a condition of being permitted to do any of the foregoing acts to use the documents only for the purposes of developing products or services in accordance with such documents and educational activities. Except as permitted by CableLabs in its sole discretion in a separate written agreement, no permission is granted to modify the documents herein (except via the Engineering Change process), or to download, use, copy, modify and/or distribute any of the documents contained herein for any other purpose, including any litigation purpose.

Technical specifications publicly available for vendors to reference are provided in PDF format only. Issued specifications undergo changes through an open Engineering Change Process. When an Engineering Change has been approved as an Engineering Change Notice (ECN), it is publicly posted on the webpage of the specific specification version against which it was written. Once ECNs are incorporated into the specification and the next version of the specification has been published, those incorporated ECNs will remain on the specification public webpage and also archived in InfoZone. If there are no ECNs against a specification, then the “Attached Documents” will be marked “No”.

To submit an Engineering Change Request (ECR) against a CableLabs specification, please complete and submit the appropriate CableLabs Engineering Change Request Form. If you have a CableLabs account, click here.


Engineering Change Notices (ECNs) have been approved for many of CableLabs®-issued specifications. The ECNs are considered part of the set of specifications—the ECNs and the issued specifications must be examined in order to fully understand specific requirements.

Consistent with current practice, Engineering Change Notices (ECNs) are Minor Changes considered to be part of the applicable specification, even though they may not yet be included in a published version of that specification. Therefore, for the purpose of compliance testing, CableLabs considers the current version of the specification to consist of the most recent, published version of the specification as it appears on CableLabs’ Web site, and any ECNs approved since the specification publication but not yet incorporated into the specification. Note that ECNs are considered mandatory for Certification/Qualification in the Certification Wave or effective date as indicated in the ECN.