[https://github.com/projectatomic/dockerfile_lint/blob/a36b3008822a0b44303ddf1ad645e3327942450c/test/data/rules/basic.yaml#L7](url) The regex for the FROM rule causes false errors if the docker repo is on a non-standard port, for example: privaterepo.mine.com:1234/repo/name:tag This is a valid FROM parameter, but fails the linter.