Is an email mailto link a valid URL?

问题:

According to the URL syntax there are supposed to be slashes after the colon following the protocol. An email link, e.g.

mailto:[e-mail]

, however, does not contain these slashes.

Can these addresses be considered valid URLs ?

回答1:

The URI standard is STD 66 which currently maps to RFC 3986.

The double slash you know from some URIs (e.g., from HTTP URIs like http://example.com/) precedes the authority component, but this authority component is not required by the generic URI syntax (only scheme and path are).

So, the mailto URI scheme is not using the authority component, and therefore there is no // after the scheme component.