End of Transmission Block


Symbol Meaning

The End of Transmission Block symbol was used in computer terminals, printers, text processing systems, and telecommunication equipment to indicate the end of a block of data being transmitted.

Its function was to divide transmitted data into blocks, allowing receiving devices to determine the boundaries of data blocks and properly process the received information. This was especially useful when data was transmitted in synchronous mode, and devices needed to have the information about when the current block of data ended and the next one began.

As for modern computer systems and applications, the U+0017 symbol is rarely used there, since other mechanisms and protocols are employed to separate and process data blocks.

Like many other control symbols, this one has no visible representation and doesn't occupy a lot of space on screen or in typed text. However, there is a separate symbol in Control Pictures2400–243F representing the graphical image of End of Transmission Block as the abbreviation ETB (End of Transmission Block) — .

The symbol “End of Transmission Block” is included in the “C0 controls” subblock of the “Basic Latin” block and was approved as part of Unicode version 1.1 in 1993.

Text is also available in the following languages: Русский;



Unicode Name End of Transmission Block
Unicode Number
CSS Code
Plane 0: Basic Multilingual Plane
Unicode Block Basic Latin
Unicode Subblock C0 controls
Unicode Version 1.1 (1993)
Keyboard shortcut ^W
Type of paired mirror bracket (bidi) None
Composition Exclusion No
Case change 0017
Simple case change 0017
scripts Common
Encoding hex dec (bytes) dec binary
UTF-8 17 23 23 00010111
UTF-16BE 00 17 0 23 23 00000000 00010111
UTF-16LE 17 00 23 0 5888 00010111 00000000
UTF-32BE 00 00 00 17 0 0 0 23 23 00000000 00000000 00000000 00010111
UTF-32LE 17 00 00 00 23 0 0 0 385875968 00010111 00000000 00000000 00000000