This Recommendation | International Standard specifies a set of basic XML Encoding Rules (BASIC-XER) that may be used to derive a transfer syntax for values of types defined in Rec. ITU-T X.680 | ISO\/IEC 8824-1 and Rec. ITU-T X.681 | ISO\/IEC 8824-2. This Recommendation | International Standard also specifies a set of Canonical XML Encoding Rules (CXER) which provide constraints on the basic XML Encoding Rules and produce a unique encoding for any given ASN.1 value. This Recommendation | International Standard further specifies a set of extended XML Encoding Rules (EXTENDED-XER) which adds further encoders options, and also allows the ASN.1 specifier to vary the encoding that would be produced by BASIC-XER. It is implicit in the specification of these encoding rules that they are also used for decoding.<\/p>\n
The encoding rules specified in this Recommendation | International Standard:<\/p>\n
are used at the time of communication;<\/p>\n<\/li>\n
are intended for use in circumstances where displaying of values and\/or processing them using commonly available XML tools (such as browsers) is the major concern in the choice of encoding rules;<\/p>\n<\/li>\n
allow the extension of an abstract syntax by addition of extra values for all forms of extensibility described in Rec. ITU-T X.680 | ISO\/IEC 8824-1.<\/p>\n<\/li>\n<\/ul>\n
This Recommendation | International Standard also specifies the syntax and semantics of XER encoding instructions, and the rules for their assignment and combination. XER encoding instructions can be used to control the EXTENDED-XER encoding for specific ASN.1 types.<\/p>\n
| PDF Pages<\/th>\n | PDF Title<\/th>\n<\/tr>\n | ||||||
|---|---|---|---|---|---|---|---|
| 2<\/td>\n | undefined <\/td>\n<\/tr>\n | ||||||
| 6<\/td>\n | Blank Page <\/td>\n<\/tr>\n | ||||||
| 7<\/td>\n | CONTENTS <\/td>\n<\/tr>\n | ||||||
| 11<\/td>\n | Introduction <\/td>\n<\/tr>\n | ||||||
| 12<\/td>\n | Blank Page <\/td>\n<\/tr>\n | ||||||
| 13<\/td>\n | 1 Scope 2 Normative references 2.1 Identical Recommendations | International Standards <\/td>\n<\/tr>\n | ||||||
| 14<\/td>\n | 2.2 Additional references 3 Definitions 3.1 ASN.1 Basic Encoding Rules (BER) 3.2 Additional definitions <\/td>\n<\/tr>\n | ||||||
| 16<\/td>\n | 4 Abbreviations 5 Encodings specified by this Recommendation | International Standard <\/td>\n<\/tr>\n | ||||||
| 17<\/td>\n | 6 Encoding instructions specified by this Recommendation | International Standard 7 Conformance 8 Basic XML encoding rules 8.1 Production of a complete BASIC-XER encoding <\/td>\n<\/tr>\n | ||||||
| 18<\/td>\n | 8.2 The XML prolog 8.3 The XML document element <\/td>\n<\/tr>\n | ||||||
| 19<\/td>\n | 8.4 Encoding of the EXTERNAL type 8.5 Encoding of the open type 8.6 Decoding of types with extension markers 9 Canonical XML encoding rules 9.1 General rules for canonical XER <\/td>\n<\/tr>\n | ||||||
| 20<\/td>\n | 9.2 Real values 9.3 Bitstring value 9.4 Octetstring value 9.5 Sequence value 9.6 Set value 9.7 Set-of value <\/td>\n<\/tr>\n | ||||||
| 21<\/td>\n | 9.8 Object identifier value 9.9 Relative object identifier value 9.10 GeneralizedTime 9.11 UTCTime <\/td>\n<\/tr>\n | ||||||
| 22<\/td>\n | 9.12 Open type value 9.13 The TIME type and the useful time types 10 Extended XML encoding rules 10.1 General <\/td>\n<\/tr>\n | ||||||
| 23<\/td>\n | 10.2 EXTENDED-XER conformance <\/td>\n<\/tr>\n | ||||||
| 25<\/td>\n | 10.3 Structure of an EXTENDED-XER encoding 11 Notation, character set and lexical items used in XER encoding instructions <\/td>\n<\/tr>\n | ||||||
| 26<\/td>\n | 12 Keywords <\/td>\n<\/tr>\n | ||||||
| 27<\/td>\n | 13 Assigning an XER encoding instruction to an ASN.1 type using a type prefix <\/td>\n<\/tr>\n | ||||||
| 29<\/td>\n | 14 Assigning an XER encoding instruction using an XER encoding control section 14.1 The encoding instruction assignment list <\/td>\n<\/tr>\n | ||||||
| 30<\/td>\n | 14.2 Identification of the targets for an XER encoding instruction using a target list 14.2.1 General rules <\/td>\n<\/tr>\n | ||||||
| 32<\/td>\n | 14.2.2 Target identification using an ASN.1 type reference and identifiers <\/td>\n<\/tr>\n | ||||||
| 33<\/td>\n | 14.2.3 Target identification using a built-in type name <\/td>\n<\/tr>\n | ||||||
| 34<\/td>\n | 14.2.4 Use of identifiers in context <\/td>\n<\/tr>\n | ||||||
| 35<\/td>\n | 14.2.5 Use of imported types identification 15 Multiple assignment of XER encoding instructions 15.1 Order in which multiple assignments are considered <\/td>\n<\/tr>\n | ||||||
| 36<\/td>\n | 15.2 Effect of assigning a negating encoding instruction 15.3 Multiple assignment of encoding instructions with multiple categories 15.4 Multiple assignment of XER encoding instructions of the same category <\/td>\n<\/tr>\n | ||||||
| 37<\/td>\n | 15.5 Permitted combinations of final encoding instructions <\/td>\n<\/tr>\n | ||||||
| 38<\/td>\n | 16 XER encoding instruction support for XML namespaces and qualified names <\/td>\n<\/tr>\n | ||||||
| 39<\/td>\n | 17 Specification of EXTENDED-XER encodings <\/td>\n<\/tr>\n | ||||||
| 40<\/td>\n | 17.1 The XML document element 17.2 The “TypeNameOrModifiedTypeName” production 17.3 The “AttributeList” production 17.4 The “ExtendedXMLValue” production <\/td>\n<\/tr>\n | ||||||
| 42<\/td>\n | 17.5 The “ExtendedXMLChoiceValue” production 17.6 The “ExtendedXMLSequenceValue” and “ExtendedXMLSetValue” productions <\/td>\n<\/tr>\n | ||||||
| 43<\/td>\n | 17.7 The “ExtendedXMLSequenceOfValue” and “ExtendedXMLSetOfValue” productions <\/td>\n<\/tr>\n | ||||||
| 44<\/td>\n | 17.8 The “ModifiedXMLIntegerValue” production 17.9 The “ModifiedXMLRealValue” production <\/td>\n<\/tr>\n | ||||||
| 45<\/td>\n | 18 The ANY-ATTRIBUTES encoding instruction 18.1 General <\/td>\n<\/tr>\n | ||||||
| 46<\/td>\n | 18.2 Restrictions 18.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 47<\/td>\n | 19 The ANY-ELEMENT encoding instruction 19.1 General 19.2 Restrictions <\/td>\n<\/tr>\n | ||||||
| 48<\/td>\n | 19.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 49<\/td>\n | 20 The ATTRIBUTE encoding instruction 20.1 General 20.2 Restrictions 20.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 51<\/td>\n | 21 The BASE64 encoding instruction 21.1 General 21.2 Restrictions 21.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 52<\/td>\n | 22 The DECIMAL encoding instruction 22.1 General 22.2 Restrictions 22.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 53<\/td>\n | 23 The DEFAULT-FOR-EMPTY encoding instruction 23.1 General 23.2 Restrictions <\/td>\n<\/tr>\n | ||||||
| 54<\/td>\n | 23.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 55<\/td>\n | 24 The ELEMENT encoding instruction 24.1 General 24.2 Restrictions 24.3 Effect on encodings 25 The EMBED-VALUES encoding instruction 25.1 General 25.2 Restrictions <\/td>\n<\/tr>\n | ||||||
| 56<\/td>\n | 25.3 Effect on encodings 26 The GLOBAL-DEFAULTS encoding instruction 26.1 General <\/td>\n<\/tr>\n | ||||||
| 57<\/td>\n | 26.2 Restrictions 26.3 Effect on encodings 27 The LIST encoding instruction 27.1 General 27.2 Restrictions <\/td>\n<\/tr>\n | ||||||
| 58<\/td>\n | 27.3 Effect on encodings 28 The NAME encoding instruction 28.1 General <\/td>\n<\/tr>\n | ||||||
| 59<\/td>\n | 28.2 Restrictions <\/td>\n<\/tr>\n | ||||||
| 60<\/td>\n | 28.3 Effect on encodings 29 The NAMESPACE encoding instruction 29.1 General <\/td>\n<\/tr>\n | ||||||
| 61<\/td>\n | 29.2 Restrictions 29.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 62<\/td>\n | 30 The PI-OR-COMMENT encoding instruction 30.1 General 30.2 Restrictions 30.3 Effect on the encodings <\/td>\n<\/tr>\n | ||||||
| 63<\/td>\n | 31 The TEXT encoding instruction 31.1 General 31.2 Restrictions <\/td>\n<\/tr>\n | ||||||
| 64<\/td>\n | 31.3 Effect on encodings 32 The UNTAGGED encoding instruction 32.1 General <\/td>\n<\/tr>\n | ||||||
| 65<\/td>\n | 32.2 Restrictions 32.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 66<\/td>\n | 33 The USE-NIL encoding instruction 33.1 General 33.2 Restrictions <\/td>\n<\/tr>\n | ||||||
| 67<\/td>\n | 33.3 Effect on encodings 34 The USE-NUMBER encoding instruction 34.1 General 34.2 Restrictions 34.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 68<\/td>\n | 35 The USE-ORDER encoding instruction 35.1 General 35.2 Restrictions <\/td>\n<\/tr>\n | ||||||
| 69<\/td>\n | 35.3 Effect on encodings 36 The USE-QNAME encoding instruction 36.1 General <\/td>\n<\/tr>\n | ||||||
| 70<\/td>\n | 36.2 Restrictions 36.3 Effect on encodings 37 The USE-TYPE encoding instruction 37.1 General 37.2 Restrictions <\/td>\n<\/tr>\n | ||||||
| 71<\/td>\n | 37.3 Effect on encodings 38 The USE-UNION encoding instruction 38.1 General 38.2 Restrictions <\/td>\n<\/tr>\n | ||||||
| 72<\/td>\n | 38.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 73<\/td>\n | 39 The WHITESPACE encoding instruction 39.1 General 39.2 Restrictions 39.3 Effect on encodings <\/td>\n<\/tr>\n | ||||||
| 74<\/td>\n | 40 Identification of the encoding rules <\/td>\n<\/tr>\n | ||||||
| 75<\/td>\n | Annex A Examples of BASIC-XER and CXER encodings A.1 ASN.1 description of the record structure A.2 ASN.1 description of a record value A.3 Basic XML representation of this record value <\/td>\n<\/tr>\n | ||||||
| 76<\/td>\n | A.4 Canonical XML representation of this record value <\/td>\n<\/tr>\n | ||||||
| 77<\/td>\n | Annex B Partial XML content and deterministic encodings B.1 Partial XML content B.2 Recommended restrictions on encodings producing partial XML element content <\/td>\n<\/tr>\n | ||||||
| 80<\/td>\n | Annex C Examples of EXTENDED-XER encodings using XER encoding instructions C.1 Introduction C.2 Simple examples C.2.1 A base-ball card <\/td>\n<\/tr>\n | ||||||
| 81<\/td>\n | C.2.2 An employee C.3 More complex examples C.3.1 Using a union of two simple types C.3.2 Using a type identification attribute <\/td>\n<\/tr>\n | ||||||
| 82<\/td>\n | C.3.3 Using enumeration values C.3.4 Using an empty encoding for a default value C.3.5 Using embedded-values for notification of a payment due <\/td>\n<\/tr>\n<\/table>\n","protected":false},"excerpt":{"rendered":" Information technology. ASN.1 encoding rules – XML Encoding Rules (XER)<\/b><\/p>\n |