Just want to make sure that a correct url must have a '/' after the domain.
1 and 4 are malformed urls, am I right? What is the RFC defining this?
Well the domain should have the / yes. Doesn't mean it can't be processed without, but you should have the '/' yes.
Does someone know what is the RFC (or other official ressource such as w3c) defining this?
URL Specifications (official sources):