Xerox Escape Sequence

Xerox Escape Sequence or XES is a page description language (PDL) developed by Xerox corporation and introduced with their 2700 laser printers in 1982. XES offers similar capabilities to Hewlett-Packard's Printer Command Language (PCL), which first appeared in 1984. XES is supported by most Xerox laser printers including the 2700. 3700, 4011, 4030, 4045, 4197, 4213, 4235, and 4700.^[1]

XES is sometimes known as UDK, from User Defined Key, the character which introduces the printer command. Commands are normally introduced by the escape character (ESC - ASCII '1B'x, EBCDIC '27'x ). This character may be changed in the data stream by the command =UDK=c, where c is the value to be used going forward. c may be any character except U, D, K, space, or 0 through 9.^[2]

XES commands perform the following functions^[2]

Fonts	Load or unload a font change font for subsequent text. Only raster fonts are supported.
Text placement	Place text in absolute position on page or relative to current position justify or center text print subscript, superscript, bold, underscore, or overstrike specify line spacing, horizontal tab vertical tab
Line drawing	draw a line between two positions on the page
Page formatting	Specify page margins set and clear horizontal tabs
Page merge	Store or unload a page of data available to merge with subsequent pages
Graphics	A graphic window is a rectangular area on a page in which a raster graphic image may be printed. The image is transmitted, in sixel encoding, following with the command, and may be magnified 1, 2, or 4 times. A graphic window may be created and stored, and called out for printing as required, for example to print a logo on each page.
Miscellaneous	Print current page specify language or use customized character mapping table reset printer data monitor mode (print datastream in hexadecimal) set or clear positions for simulated carriage control tape