Code page and national language support terminology
The term code page is used to refer to a number of different concepts.
Conversely, the set of concepts to which code page can refer can also be described by a
number of other terms. The concept and implementation of code pages also differ
significantly between Windows, Linux, and the UNIX system.
To describe the types of character data that users can enter and store in an Rational® ClearQuest® environment, this discussion uses the following terms:
- A national language support (NLS) provides commands and library subroutines for a single worldwide system base. In the context of Rational ClearQuest, NLS refers to the ability of Rational ClearQuest applications and databases to input and output data consisting of characters from any of the supported Rational ClearQuest data code pages.
- The term character set refers to a set of characters that a computer application or system supports.
- The term code page, refers to a character set and
the binary values that represent those characters. A computer or application
can use code pages to work with these characters:
- Only the 128 characters of the ASCII character set (suitable for American English).
- Additional characters used by Eastern and Western European languages, such as "ä" for German, Swedish and Finnish and "È" for French and Spanish, and so on.
- Characters from non-European languages such as Hebrew, Japanese, and Chinese.
- Additional characters required by other languages.
- The term vendor database character set refers to a character set that the database management system (DBMS) vendor allows to be stored in the databases for the Rational ClearQuest schema repository and user data. Individual DBMS vendors use code page, code set, collation, and charset as synonyms for this term.
- The term Rational ClearQuest data code page refers to character set that Rational ClearQuest can store in a Rational ClearQuest database set. This character set is equivalent to or a subset of the corresponding vendor database character set. To set the data code page, you must select the value compatible with the vendor database character set that is configured for the vendor database. A schema repository can support only one data code page.
- The term local character set (generally called the locale on Linux and the UNIX systems) refers to the character set that can be entered or displayed in a command-line shell on the system that runs a Rational ClearQuest application, for example, the Maintenance Tool, Designer, or Rational ClearQuest client. On Linux or the UNIX system , the local character set is controlled by the LANG environment variable. On Windows, it is controlled by settings in the Regional and Language Options. Other character sets can be displayed if additional fonts are configured. Also, additional character data may be entered through an input method editor (IME) or by cutting and pasting text to the Rational ClearQuest GUI applications.