Previously, when creating an autolink reference for a repository, you could only use a numeric identifier in the
<num> parameter. This format didn't support integration with platforms that use alphanumeric identifiers, like the last segment of this Trello card URL:
https://trello.com/c/3eZr2Bxw. Now you can create an autolink with an alphanumeric identifier.
Any previously created autolinks will continue to support only numeric identifiers so that they continue working as before. Only newly created autolinks will support alphanumeric identifiers.
Autolinks are available in repositories with GitHub Pro, GitHub Team, GitHub Enterprise Cloud, and GitHub Enterprise Server. For more information, see GitHub's products.