Code page

In computing, a code page is a character encoding and as such it is a specific association of a set of printable characters and control characters with unique numbers. Typically each number represents the binary value in a single byte. (In some contexts these terms are used more precisely; see Character encoding § Terminology.)

The term "code page" originated from IBM's EBCDIC-based mainframe systems,^[1] but Microsoft, SAP,^[2] and Oracle Corporation^[3] are among the vendors that use this term. The majority of vendors identify their own character sets by a name. In the case when there is a plethora of character sets (like in IBM), identifying character sets through a number is a convenient way to distinguish them. Originally, the code page numbers referred to the page numbers in the IBM standard character set manual,^[4]^[5]^[6] a condition which has not held for a long time. Vendors that use a code page system allocate their own code page number to a character encoding, even if it is better known by another name; for example, UTF-8 has been assigned page numbers 1208 at IBM, 65001 at Microsoft, and 4110 at SAP.

Hewlett-Packard uses a similar concept in its HP-UX operating system and its Printer Command Language^[7] (PCL) protocol for printers (either for HP printers or not). The terminology, however, is different: What others call a character set, HP calls a symbol set, and what IBM or Microsoft call a code page, HP calls a symbol set code. HP developed a series of symbol sets,^[8]^[9] each with an associated symbol set code, to encode both its own character sets and other vendors’ character sets.

The multitude of character sets leads many vendors to recommend Unicode.

^ Cite error: The named reference IBM_i_EBCDIC was invoked but never defined (see the help page).
^ Cite error: The named reference SAP_CP was invoked but never defined (see the help page).
^ Cite error: The named reference oracle.com was invoked but never defined (see the help page).
^ Cite error: The named reference DEC_VT510 was invoked but never defined (see the help page).
^ Cite error: The named reference DEC_1994_Codepage was invoked but never defined (see the help page).
^ Cite error: The named reference Paul_2001_CODEPAGE was invoked but never defined (see the help page).
^ Cite error: The named reference PCL was invoked but never defined (see the help page).
^ Cite error: The named reference PCL-Symbol was invoked but never defined (see the help page).
^ Cite error: The named reference PCL5 was invoked but never defined (see the help page).

[IBM_i_EBCDIC-1] Cite error: The named reference IBM_i_EBCDIC was invoked but never defined (see the help page).

[SAP_CP-2] Cite error: The named reference SAP_CP was invoked but never defined (see the help page).

[oracle.com-3] Cite error: The named reference oracle.com was invoked but never defined (see the help page).

[DEC_VT510-4] Cite error: The named reference DEC_VT510 was invoked but never defined (see the help page).

[DEC_1994_Codepage-5] Cite error: The named reference DEC_1994_Codepage was invoked but never defined (see the help page).

[Paul_2001_CODEPAGE-6] Cite error: The named reference Paul_2001_CODEPAGE was invoked but never defined (see the help page).

[PCL-7] Cite error: The named reference PCL was invoked but never defined (see the help page).

[PCL-Symbol-8] Cite error: The named reference PCL-Symbol was invoked but never defined (see the help page).

[PCL5-9] Cite error: The named reference PCL5 was invoked but never defined (see the help page).

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