51.4.1 iso Execution Mode Rules

quoted-name ::= quoted-atom
| backquoted-atom

base-prefix ::= 0b { indicates base 2 }
| 0o { indicates base 8 }
| 0x { indicates base 16 }

char-item ::= quoted-item

other-escape-sequence ::= x alpha... \ {treating a,b,... and A,B,... as 10,11,... } in the range [0..15], hex character code }
| o digit... \ { in the range [0..7], octal character code }
| <LFD> { ignored }
| \ { stands for itself }
| ' { stands for itself }
| " { stands for itself }
| ` { stands for itself }

quoted-char ::= <SPC>
| printing-char