ANSI INCITS ISO IEC 14957-1996 Information technology Notation of format for data element values.pdf

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1、INCITS/ISO/IEC 14957:19962009 (ISO/IEC 14957:1996, IDT) Information technologyNotation of format for data element valuesINCITS/ISO/IEC 14957:19962009(ISO/IEC 14957:1996, IDT)INCITS/ISO/IEC 14957:19962009 ii ITIC 2009 All rights reserved PDF disclaimer This PDF file may contain embedded typefaces. In

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4、 printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. Adopted by INCITS (InterNational Committee for Information Technology

5、 Standards) as an American National Standard. Date of ANSI Approval: 3/23/2009 Published by American National Standards Institute, 25 West 43rd Street, New York, New York 10036 Copyright 2009 by Information Technology Industry Council (ITI). All rights reserved. These materials are subject to copyri

6、ght claims of International Standardization Organization (ISO), International Electrotechnical Commission (IEC), American National Standards Institute (ANSI), and Information Technology Industry Council (ITI). Not for resale. No part of this publication may be reproduced in any form, including an el

7、ectronic retrieval system, without the prior written permission of ITI. All requests pertaining to this standard should be submitted to ITI, 1250 Eye Street NW, Washington, DC 20005. Printed in the United States of America 996(E) Foreword IS0 (the International Organization for Standardization) and

8、IEC (the International Electrotechnical Commission) form the specialized system for worldwide standardization. National bodies that are members of IS0 or IEC participate in the development of International Standards through technical committees established by the respective organization to deal with

9、 particular fields of technical activity. IS0 and IEC technical committees collaborate in fields of mutual interest. Other international organizations, governmental and non-governmental, in liaison with IS0 and IEC, also take part in the work. In the field of information technology, IS0 and IEC have

10、 established a joint technical committee, ISOAEC JTC 1. Draft International Standards adopted by the joint technical committee are circulated to national bodies for voting. Publication as an International Standard requires approval by at least 75 % of the national bodies casting a vote. This Interna

11、tional Standard ISOAEC 14957 was prepared by Joint Technical Committee ISOAEC JTC 1, Information technology, Subcommittee SC 14, Data element principles. INCITS/ISO/IEC 14957:19962009 ITIC 2009 All rights reservedIntroduction Data interchange is experiencing rapid expansion, in the commercial, techn

12、ical and public sectors. It gives rise to inter working between different communities which often have developed independently information processing applications and telecommunication networks which meet specific needs. Hence an overall situation which suffers from a lack of homogeneity. In order t

13、o remedy this situation, an urgent standardization effort focused in particular on the representation of data elements is necessary. The representation of a data element supposes in the first place that the format, i.e. the type of characters used in the representation and in the length of the latte

14、r is specified. So that these specifications have the same significance for everyone involved, it is necessary to express them in accordance with standardized conventions. Such rules are likely to eliminate any and all risk of ambiguity, lack of understanding and error; they also facilitate the comp

15、arison of data element dictionaries, the design and creation of information systems as well as electronic data interchange (EDI). These notations have been partially and variously expressed in different International Standards according to the specific contexts in which they have been defined, e.g.

16、EDIFACT (IS0 9735), Banking Standards (as IS0 7982-l), Character sets (IS0 8859), Information processing (IS0 6093). Therefore, the objective of this International Standard is to provide a unique source of reference on this issue for all Standards utilizing these type of notations independently of t

17、heir environments. iv INCITS/ISO/IEC 14957:19962009 ITIC 2009 All rights reservedInformation technology - Notation of format for data element values 1 Scope This International Standard specifies the notation to be used for stating the format, i.e. the character types used in the representation of da

18、ta elements and the length of these representations. It also specifies additional notations relative to the representation of numerical figures. The scope of this International Standard is limited to graphic characters as digits, letters and special characters. It does not cover control characters.

19、These rules are applicable wherever there is reason for specifying these characteristics. Applications include data elements dictionaries, the processing of information and EDI. 2 Normative References The following standards contain provisions which, through reference in the text, constitute provisi

20、ons of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of standards ind

21、icated below. Members of IEC and IS0 maintain reaisters of currentlv valid International Standards. IS0 2382.4:1987, Information processing systems - Vocabulary - Parl 04: Organization of data. IS0 6093: 1985, Information processing - Representation of numerical for information interchange. values i

22、n character strings ISO/IEC 11179-3:1994, Information techno/ogy - Specification and standardization of data elements - Part 3: Basic attributes of data elements. I EC 1360-l : 1995, Standard data element types with associated classification scheme for electric components - Pati 1: Definitions - Pri

23、nciples and methods. 3 Definitions For the purposes of this International Standard, the following definitions apply. 3.1 data element : A unit of data for which the definition, identification, representation and permissible values are specified by means of a set of attributes (lSO/lEC 11179-3). 3.2

24、character set : A finite set of different characters that is complete for a given purpose (IS0 2382-4) 3.3 character type : A set of characters of the same kind or having the same use. Examples: letters, figures, special characters, etc. 3.4 length (of representation) : A number of characters used t

25、o represent a data element. INCITS/ISO/IEC 14957:19962009AMERICAN NATIONAL STANDARD ITIC 2009 All rights reserved4 Notation relative to character types and length of representation of a data element The type and the number of characters shall be specified in order to represent a data element. 4.1 Ch

26、aracter type notation The following rules apply to printable character types used in the representation of data elements and defined in the IS0 standards. The rules do not include communication control codes or field separators. Character types are represented by the following notation. 4.1.1 Normal

27、 types A : Capital letters (A to Z) a : Small letters (a to z) n : figures (0 to 9) 4.1.2 mixed types Aa : Capital letters (A to Z) and/or small letters (a to z) An : Capital letters (A to Z) and/or figures (0 to 9) an : Small letters (a to z) and/or figures (0 to 9) Aan : Capital letters (A to Z) a

28、nd/or smal 4.1.3 Extended types This category concerns character sets exte standardized. The following notation is used : letters (a to z) and/or figures (0 to 9) lded to signs other than letters and figures which are s: all permitted characters of an authorized set 2 INCITS/ISO/IEC 14957:19962009 I

29、TIC 2009 All rights reservedOne of the following notation shall be used to specify the set to which it is referred to: sa: all permitted characters from the character set authorized by IS0 8859-l sb: all permitted characters from the character set authorized by IS0 8859-2 SC: all permitted character

30、s from the character set authorized by IS0 8859-5 sd: all permitted characters from the character set authorized by IS0 8859-7 4.2 Length The length of a data element representation can be fixed or variable 4.2.1 Fixed length This notation expresses a fixed length by writing after the character type

31、, without any space or intermediate character, the number of characters representing the data element. EXAMPLES : a3 : Fixed length of 3 small letters n6 : Fixed length of 6 figures 4.2.2 Variable length A variable length is expressed by writing two dots: “” after the indication of the type of chara

32、cters a) Variable length up to a defined maximum number of characters This notation expresses a variable length up to a defined maximum number of characters by writing after the character type and with no intermediate space, the variable length notation followed by the maximum number of characters E

33、XAMPLES : a6 : variable length up to a maximum of 6 small letters An5 : variable length up to a maximum of 5 capital letters and/or figures sa16 : variable length up to a maximum of 16 characters (of the authorized set IS0 8859-l). b) Variable length between a defined minimum and maximum number of c

34、haracters This notation expresses a variable length between a defined minimum and maximum number of characters by writing after the character type, the minimum number of characters and the variable length notation followed by the maximum number of characters “Additional notation might be added INCIT

35、S/ISO/IEC 14957:19962009 ITIC 2009 All rights reservedEXAMPLES : a36 : variable length from 3 to 6 small letters an69 : variable length from 6 to 9 small letters and/or figures 4.2.3 Length expressed by a number of lines of characters A data element representation occasionally requires several lines

36、 of characters. These lines can be of fixed or variable length up to a defined maximum number. This notation for expressing a number of lines is this number preceded by the letter “x”, after the indication of the length of the line established as indicated in 4.2.1 and 4.2.2. EXAMPLES : an35 x 4 : 4

37、 lines having a maximum of 35 small letters and/or figures sb 25 x 5 : 5 lines each having 25 characters (of the authorized set IS0 8859-2:1987, Information processing - 8 bit single byte ruded graphic character sets - Part2 : Latin alphabet No.2). 5 Additional notation for figures The rules which a

38、re specified in the preceding clauses also apply to figures. Nevertheless, it may be desirable to distinguish numeric values by means of a specific notation 5.1 Numeration system It may be necessary to indicate which numeration system is used to represent a data element. This will be done by using o

39、ne of the following notation which is shown in the table below. It only includes the main numeration systems commonly in use*. Notation Numeration system Numeration IB asis I B 1 Binarv 12 I 0 I Octal 18 I D 1 Decimal I10 I H 1 Hexadecimal 116 I S I Sexaqesimal I60 I This letter will be placed after

40、 the one representing the character type and before the indication of the length. When nothing is mentioned, the numeration system is supposed to be decimal (basis 10). 2AdditionaP notation might be added 4 INCITS/ISO/IEC 14957:19962009 ITIC 2009 All rights reserved5.2 Notation for non computable fo

41、rmat specification 5.2.1 Numbers The numerical notation is specified by indication of the small letter In” followed, with no intermediate space or character, by the maximum number of digits that can be present in this number. EXAMPLE : n3: numbers from 000 to 999 5.2.2 Positive and negative numbers

42、a) explicit notation: use of the plus “+” or minus I-” sign placed before the small letter “n” EXAMPLES : +n2 : -n3 : b) positive numbers from 00 to 99 negative numbers from -999 to 000. implicit notation can be used for the positive sign EXAMPLE : n4 : positive numbers from 0000 to 9999. c) the sma

43、ll letter “n” can be replaced by the capital letter IN” to indicate that a given number may have a negative value. EXAMPLE : N2 positive or negative numbers from -99 to +99, including 0. 5.3 Notation for computable format specification 5.3.1 Types of computable formats The human oriented expressions

44、 in IS0 6093 and IEC 1360-l are similar to the formal format notations to be used in specifications as specified in this International Standard : I : integer formats (I conforms to “NW) ; D : decimals formats (D conforms to “NR2”) ; F : floating comma (F conforms to “NR3). A letter S indicates that

45、the value may be negative. INCITS/ISO/IEC 14957:19962009 ITIC 2009 All rights reserved5.3.2 Integer formats An integer indicates the maximum length in number of digits. EXAMPLES : I6 . . an integer computable format of maximum 6 digits. IS6 : an integer computable format of maximum 6 digits which ma

46、y have negative values 5.3.3 Decimal formats A decimal number is composed of an integer part and a decimal part. - an integer indicates the maximum length in number of digits ; - following a full stop, a further integer indicates the maximum number of decimal positions. EXAMPLES : D12.3 a decimal co

47、mputable format of maximum twelve digits of which maximum three may be to the right of the decimal mark. 5.3.4 Floating comma format Numbers with a floating comma are expressed according to the convention for the representation of values with exponents (IS0 6093). - an integer indicates the maximum

48、length in number of digits ; - following a full stop, a further integer indicates the maximum number of decimal positions ; - following a letter E, a letter S indicates the exponent may be negative ; - a further integer indicates the maximum length of the exponent. NOTE - It is recognized that the “

49、floating comma” format referred to in this International Standard is called “floating point” in some countries. The term “floating comma” is used in this International Standard to conform to IS0 31. INCITS/ISO/IEC 14957:19962009 ITIC 2009 All rights reservedEXAMPLES : F6.3E2 a floating comma computable format with a significand of maximum six digits of which maximum three may be to the right of the decimal mark and with an exponent of maximum two digits. F4.3ES3 a floating comma computable format with a significand of maximum four digit