Source note · E.164 numbering and dial string normalization
The tel URI defines an 'extension' parameter for extensions and an 'isdn-subaddress' parameter for ISDN subaddresses.
Checked 2026-09-23
- Vendor
- IETF
- Product
- tel URI
- Subsystem
- syntax
- Deployment
- standard
- Region
- not restricted
- Release range
- RFC 3966
- Checked
- 2026-09-23
Sources
- RFC 3966: The tel URI for Telephone Numbers — IETF / RFC Editor · tier 1 standards and regulators · Sections 5.2 ISDN Subaddresses and 5.3 Phone Extensions
Cite this note
APA
WarmTransfer. (2026, September 23). E.164 numbering and dial string normalization: source note e164-numbering-tel-extension-param. WarmTransfer. https://warmtransfer.net/knowledge/claims/e164-numbering-tel-extension-param
BibTeX
@misc{warmtransfer-claim-e164-numbering-tel-extension-param,
title = {E.164 numbering and dial string normalization: source note e164-numbering-tel-extension-param},
author = {{WarmTransfer}},
year = {2026},
url = {https://warmtransfer.net/knowledge/claims/e164-numbering-tel-extension-param},
note = {Source note e164-numbering-tel-extension-param, checked 2026-09-23}
}