Support format like "5:1" as well as "5:01"

[Eteon]

"5:1" returns None whereas "5:01" returns 301.

[cackovic]

I’m thinking to myself if this format should be supported and as I think about that, I also wonder if maybe we should have a configuration setting that allows a grammar to be set by the user so the user can allow or disallow formats like this. Thoughts?