Question

I noticed that Wikipedia links pointing to a path on a different Wikipedia subdomain use a link with the following syntax: //<SERVER_NAME>/<REQUEST_URI>. For example, a link from a file page to the file appears (for example) as //upload.wikimedia.org/wikipedia/en/9/95/Stack_Overflow_website_logo.png. I am familiar with absolute paths (thinking twice about that now) and relative paths and how to use them. However, I have never seen this use. I assume this points to a new server name using the current protocol. Is this correct? And is there an official name (or widely accepted name) for this?

Answer 1

It looks like these //example.com URIs are called "Scheme Relative" or "Protocol Relative", and there is more information about it at this question:

Network-Path Reference URI / Scheme relative URLs

EDIT:

Apparently this might actually be called a "network-path reference" as seen here:
https://www.rfc-editor.org/rfc/rfc3986#section-4.2

Quote:

A relative reference that begins with two slash characters is termed
a network-path reference; such references are rarely used. A
relative reference that begins with a single slash character is
termed an absolute-path reference. A relative reference that does
not begin with a slash character is termed a relative-path reference.