Toolman

ASCII 18

ASCII 18 is Device Control 2 — the control character DC2.

Every representation

CharacterDC2 (not printable)
NameDevice Control 2
Decimal18
Hexadecimal0x12
Octal0022
Binary00010010
HTML entity
Escape sequence\x12
UnicodeU+0012
KeyboardCtrl+R
GroupControl character

What it is for

A general device control signal with no fixed modern meaning.

Where the number comes from

Codes 0 to 31 were reserved for control: instructions to a teleprinter rather than characters to print. Code 18 is Ctrl+R because the Ctrl key was originally wired to clear the top two bits of whatever you typed, mapping the letter R at 82 down to 18.

Frequently asked questions

What is ASCII 18?

Device Control 2 (DC2), a control character. In hexadecimal it is 0x12, in octal 0022, and in binary 00010010.

How do I type ASCII 18?

Press Ctrl+R in a terminal. In a string literal you can write it as \\x12 in most languages.

Is ASCII 18 printable?

No. Codes 0 to 31 and 127 are control characters — they were instructions to a teleprinter rather than marks on paper, and most terminals show nothing for them.

Nearby codes

Full ASCII table · Text to binary converter · Number base converter