NLA - Glossary
Definitions given by some sources are marked with [CBEMA], [IBM] or [ISO]. Other explanations reflect common understanding of people dealing with these subjects (typographers, printers and so on).
- American Standard Code for Information Interchange. A coded character set consisting of 128 7-bit characters. There are 32 control characters, 94 graphic characters, the space character and the delete character.
- [IBM] Country Extended Code Pages. A number of single-byte EBCDIC coded character sets in the IBM corporate registry. Each code page contains the same character set, with the identifier of 00697 (also known as Latin Alphabet Number 1), but with different code point allocations.
- a) [ISO] A member of a set of elements used for organisation control or representation of data. A character can be a graphic
character or a control character.
b) Common term for glyph used in writing languages.
- children tag
- Identification of elements which are hierarchically lower than the element defined by the «parent tag». For example
in a data base, a row is subsidiary to a table, an element is subsidiary to a row. The table may be tagged to be «French»,
whereas a specific element ma be tagged «Turkish».
To ease processing, it is convenient to indicate the fact, whether children-tags exist or not.
- coded character set
- [ISO] A set of unambiguous rules that establish a character set and the one-to-one relationship between the characters of the set and their coded representations. synonymous with code.
- code page
- [IBM] A specification of code points for each graphic character in a set or in a collection of graphic character sets. Within a code page, a code point can have only one specific meaning.
- code point
- a) [IBM] A unique bit pattern defined in a code. Depending on the code, a code point can be 7-bits, 8-bits, 16-bits, or other.
Code points are assigned graphic characters in a code page.
b) Location in a coding scheme. There are several notations of this position. In ISO the position is defined by its row/column in the code table (e.g. 5/14). In the IBM environment the hexadecimal representation of the location is prefered (e.g. X'5E').
- control character
- a) [ISO] A control function, the coded representation of which consists of a single bit combination.
b) [IBM] A character whose occurence in a particular context initiates, modifies, or stops a control function.
- control function
- a) [ISO] An element of a character set that affects the recording, processing, transmission, or interpretation of data, and
that has a coded representation of one or more bit combinations.
b) A sequence of coded characters to which a special meaning is assigned. Many of these sequences start with the escape character. Hence they are called escape sequence.
- [IBM] Extended Binary Coded Decimal Interchange Code. A coded character set consisting of 8-bit coded characters.
- a) [CBEMA] A family or assortment of characters of a given size and style; for example, 9 point Bodoni Modern.
b) A collection of graphic presentations of a character set. For example the font «Helvetica» may consist of character shapes appearing in bold, normal and thin (fainted) as well as these in slanted variants. Depending on the printing technology also the variation in size of the printed characters must be represented in the fonts.
- A graphic shape. The name given to the shape defines the meaning. For example the shape B may be the second character in our latin alphabet or the third letter in the cyrillic alphabet (pronounced like our w). The shape ³ may have the name «greater then or equal symbol».
- graphic character
- a) [ISO] A character, other than a control function, that has a visual representation normally handwritten, printed or displayed.
b) [IBM] A graphic symbol such as a numeric, alphabetic, or special character, or ideogram.
- Intelligent Printer Data Stream. Datastream consisting of structured fields to control a printer. Functions are grouped into classes. A specific printer normally can perform only a set of function classes, not the total set of functions specified in IPDS.
- [ISO] A set of characters, conventions, and rules, that is used for conveying information. The three aspects of language are pragmatics, semantics, and syntax.
- A utility in «UNIX» implementations to specify an environment: names of characters, coding of characters, sort rules, patterns for presentation of numeric values and currency values, patterns for representation of date and time strings.
- [IBM] National Language Support. The ability for users to communicate with applications in the language most familiar to them.
- Name of Standard for a Portable Unix, which is IEEE's family of 1003.x standards. Hence POSIX also is a family of standards. All the POSIX standards are also incorporated in ISO/IEC 9945-x standards.
- System Application Architecture.
Layered approach to make applications more flexible and build on common components.
Software Magazine, Nov. 1988: IBM Corp's Systems Application Architecture (SAA) will have a major impact on systems technologies over the next decade because the standard recognizes that connectivity, networks, and communications standards will be the driving force in future corporate applications. Distributed processing will predominate with three goals: access to distributed data, access of system resources by PC and workstation users and transparent distribution of machine tasks. SAA will work on all IBM platforms from the System 370 to AS-400 and System 3x midrange systems to OS-2-based Personal System 2 PCs. The four major components of SAA that will provide consistent interface to these systems … See also IBM Systems Journal
- Library routine of POSIX (Portable UNIX) to set the appropriate locale for the application. A locale is an environment variable, pointing to information related to language, character code, date format and other categories. This information is put together with the utility localdef.
- sort key
- a) Data structure built from text data. The information contained in the original string of characters (for example «LaBonté»)
is separated into strings of attributes. For example base characters (labonte), accents (... «accaigue»), case information
(«uc»«lc»«uc»....) and so on. The purpose of this method is to ease processing.
b) Translation of textual data to binary values which can be sorted by numeric comparison. This transformation is necessary to get a contiguous set of binary values from the incontiguous set of character codes.
- special character
- [IBM] A graphic character that is not a letter, a digit, or a space character.
- A graphic shape of arbitrary purpose. This may be characters (used for alphabetic languages), mathematical symbols, punctuation symbols or ideographic characters or the like. In ISO-terms this is called a glyph.
- syntactic character set
- a) [IBM] A set of 81 graphic characters registered in the IBM registry as character set 00640. This set was originally recommended
to the programming language community to be used for syntactic purposes towards maximising portabaility and interchangability
across systems and country boundaries. It is contained in most of the primary registered character sets, with a few exceptions.
b) Characters and symbols from this set have the same code in all IBM single-byte code pages, in particular the country extended code pages and the international code page. But this set also lacks some special symbols common to modern programming languages.
- a) [IBM] A mechanism used to identify certain attributes having some bearing on handling of character data. Some examples are
character set identifier, code page identifier, language identifier, country indentifier, and encoding scheme identifier.
b) Identification of objects, which can be handled independently of the object (like a price tag on a banana). The tag may contain information or only point to it (for example, if the information is very complex like a rule to sort French text). In this case the tag is an identification of information about the object (the text in French).
Tags can be held in data dictionaries or in close connection to the data (for example in communications, where data blocks are preceeded by information about the data).
- Name of a Technical Subcommittee of (see POSIX). The UNIX user group UniForum has trademarked this name. UniForum is «The International Association of UNIX System Users».