All reports of vcs-field-uses-not-recommended-uri-format for the archive. The extended description of this tag is:
The VCS-* field uses a URI which doesn't match the recommended format, but still looks valid. Examples for not recommended URI formats are protocols that require authentication (like SSH). Instead where possible you should provide a URI that is accessible for everyone without authentication.
This renders debcheckout(1) unusable in these cases.
This tag has not been emitted in any package tested by Lintian.