A character set is an ordered set of unique representations called characters; for example, the set of symbols in Morse code, or the letters of the Cyrillic alphabet are character sets. PL/I supports all PC character sets. Character set 0640 is called the invariant character set because a character from this set has the same code point in all code pages. A code point is a one-byte code representing one of 256 potential characters; a code page is an assignment of graphic characters and control function meanings to all of the code points.
PL/I supports all code pages that conform to character set 0640; however, PL/I assumes code page 0850 for all code points, except for those characters which are specified by the programmer using the CURRENCY, NAMES, OR, or NOT compiler options. For more information on these options, refer to the Programming Guide.
Code page 0850 contains the English alphabet, ten decimal digits, special characters, and other national language and control characters. Constants and comments can contain any SBCS character value. PL/I elements (for example, statements, keywords and delimiters) are limited to the characters described in the following sections.