What is the semicolon reserved for in URLs?

Question

The RFC 3986 URI: Generic Syntax spec lists a semicolon as a reserved (sub-delim) character:

reserved    = gen-delims / sub-delims

gen-delims  = \":\" / \"/         


        

Answer 1

The intent is clearer if you go back to older versions of the specification:

  path_segments = segment *( "/" segment )
  segment       = *pchar *( ";" param ) 

Each path segment may include a sequence of parameters, indicated by the semicolon ";" character.

I believe it has its origins in FTP URIs.