Repository Designators (ERGO User Manual)

A project or a dependency is designated by one of:

the git url itself: ‘https://gitlab.com/com-informatimago/com-informatimago.git’ or ‘git@github.com:informatimago/lisp.git’;
a collection-qualified designator: the name of a collection and the path of the repository in it — ‘gitlab:owner/repo’ in the shell and AutoLISP syntax, ‘(gitlab "owner/repo")’ in Common Lisp;
a simplified designator: the path alone — ‘owner/repo’; the collections are searched, and when several match, you are asked to choose. Simplified designators are accepted interactively, but not in project files.

A version may be attached to the designator; without one, the repository’s default branch is tracked: