URI Grammar

uri‑reference → absolute‑uri | relative‑ref
absolute‑uri → scheme colon hier‑part (quest query)? (hash fragment)?
scheme → scheme‑char+
scheme‑char → alpha | digit | dash | plus | dot
hier‑part → slash slash authority path‑abempty | path‑absolute | path‑rootless | path‑empty
relative‑ref → relative‑part (quest query)? (hash fragment)?
relative‑part → slash slash authority path‑abempty | path‑absolute | path‑noscheme | path‑empty
authority → (user‑info at)? host (colon port)?
user‑info → (unreserved | pct‑encoded | sub‑delims | colon)*
host → ip‑literal | ipv4‑address | reg‑name
ip‑literal → lbracket (ipv6‑address | ipv‑future) rbracket
ipv4‑address → digit+ dot digit+ dot digit+ dot digit+
ipv6‑address → ipv6‑char+
ipv6‑char → digit | hx | colon | dot | slash
ipv‑future → alpha (digit | hx)+ dot (unreserved | sub‑delims | colon)+
port → digit*
reg‑name → (unreserved | pct‑encoded | sub‑delims)*
path‑abempty → (slash segment)*
path‑absolute → slash segment‑nz (slash segment)*
path‑noscheme → segment‑nz‑nc (slash segment)*
path‑rootless → segment‑nz (slash segment)*
path‑empty → <empty>
segment → pchar*
segment‑nz → pchar+
segment‑nz‑nc → (unreserved | pct‑encoded | sub‑delims | at)+
query → (pchar | slash | quest)*
fragment → (pchar | slash | quest)*
pchar → unreserved | pct‑encoded | sub‑delims | colon | at
unreserved → alpha | hx | digit | dot | dash | underscore | tilde
reserved → gen‑delims | sub‑delims
gen‑delims → colon | slash | quest | hash | lbracket | rbracket | at
sub‑delims → exclamation | dollar | amp | sq | lparen | rparen | asterisk | plus | comma | semicolon | eq
pct‑encoded → percent hex hex
hex → digit | hx