The following table list all valid values that can be used in an equivalent class expression [=class=]:
| Symbolic | Character |
|---|
| NUL | \x00 |
| SOH | \x01 |
| STX | \x02 |
| ETX | \x03 |
| EOT | \x04 |
| ENQ | \x05 |
| ACK | \x06 |
| alert | \x07 |
| backspace | \x08 |
| tab | \t |
| newline | \n |
| vertical-tab | \v |
| form-feed | \f |
| carriage-return | \r |
| SO | \xE |
| SI | \xF |
| DLE | \x10 |
| DC1 | \x11 |
| DC2 | \x12 |
| DC3 | \x13 |
| DC4 | \x14 |
| NAK | \x15 |
| SYN | \x16 |
| ETB | \x17 |
| CAN | \x18 |
| EM | \x19 |
| SUB | \x1A |
| ESC | \x1B |
| IS4 | \x1C |
| IS3 | \x1D |
| IS2 | \x1E |
| IS1 | \x1F |
| space | \x20 |
| exclamation-mark | ! |
| quotation-mark | " |
| number-sign | # |
| dollar-sign | $ |
| percent-sign | % |
| ampersand | & |
| apostrophe | ' |
| left-parenthesis | ( |
| right-parenthesis | ) |
| asterisk | * |
| plus-sign | + |
| comma | , |
| hyphen | - |
| period | . |
| slash | / |
| zero | 0 |
| one | 1 |
| two | 2 |
| three | 3 |
| four | 4 |
| five | 5 |
| six | 6 |
| seven | 7 |
| eight | 8 |
| nine | 9 |
| colon | : |
| semicolon | ; |
| less-than-sign | < |
| equals-sign | = |
| greater-than-sign | > |
| question-mark | ? |
| commercial-at | @ |
| left-square-bracket | [ |
| backslash | \ |
| right-square-bracket | ] |
| circumflex | ^ |
| underscore | _ |
| grave-accent | ` |
| left-curly-bracket | { |
| vertical-line | | |
| right-curly-bracket | } |
| tilde | ~ |
| DEL | \x7F |
| EXAMPLE | [[=NUL=]] will match a NUL character.
[\x00] will also match a NUL character. |
|---|
