The documentation recommends to use portlint to check conformance with guidelines.
However, when reading portlint's man page, it seems "portlint <directory>" is enough, but when submitting the new port, you get an error report from which you realize you should have used portlint -C instead (and possibly also -A).
The porter's handbook should mention the options to use with portlint to perform the same level of verification as when the new port will be submitted.
I would add documentation that states committers should use -C prior to committing a port. When building a new port, use -N (and maybe -C as well) to check it.