http://www.rfc-editor.org/rfc/rfc1808.txt
RFC 1808: Relative Uniform Resource Locators, R. Fielding1995-06-01T23:00:00-00:00In situations where the base URL is well-defined and known to the parser (human or machine), it is useful to be able to embed URL references which inherit that context rather than re-specifying it in every instance. This document defines the syntax and semantics for such Relative Uniform Resource Locators. [STANDARDS-TRACK]