Interconnection World Glossary: X.21, The Physical Layer protocol of X.25,X.25, A still-popular data protocol, X.400, A standard for electronic mail exchange

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Numbers & Misc. \| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

X.21	The Physical Layer protocol of X.25

X.25	A still-popular data protocol

X.400	A standard for electronic mail exchange

X.500	An ITU family of directory services

X.509	ITU standard defining formats for digital certificates and CRL (Certificate Revocation Lists)

XDSL	A generic acronym for the suite of DSL services, where thee « x » can be replaced with any of a number of letters. (ADSL, ADSL2, ADSL2+, HDSL, HDSL2, SDSL, SHDSL, VDSL, etc.)

XHTML	Extensible Hypertext Markup Language

XMISSION	Transmission

XMIT	Transmit

XML	Extensible Markup Language

Xmodem	File transfer protocol

XO	Crystal Oscillator

XOFF	ASCII Transmitter Off Character

XON	ASCII Transmitter On Character

XT	Crosstalk

x-y Mount	Altazimuth Mount

XON/XOFF	Abbreviation for transmitter on/transmitter off.