IEC International ISO Standard ISO/IEC25390 Information technology - Financial First edition information exchange - Simple 2025-04 binary encoding Referencenumber ISO/IEC25390:2025(en) ?ISO/IEC2025 IS0/IEC25390:2025(en) COPYRIGHTPROTECTEDDOCUMENT IS0/IEC2025 be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying,or posting on or Iso's member body in the country of the requester. ISo copyright office CP 401:Ch.de Blandonnet 8 CH-1214Vernier,Geneva Phone: +4122 749 0111 Email:[email protected] Website:www.iso.org Published in Switzerland @IS0/IEC2025-All rights reserved ii IS0/IEC25390:2025(en) TableofContents Tableof Contents iii Foreword. ..vii Introduction... .viii 1 Scope... 2 Normativereferences Terms and definitions.. 3 3.1 datatype. 3.2 encoding. 3.3 field.. 3.4 messageschema 3.5 messagetemplate. 3.6 session protocol.. 3.7 XML schema.... 3.8 Specification terms. oObjectives.. 4 4.1 General. 4.2 Binary type system 4.3 Design principles. 4.4 Message schema 4.5 Documentation. 4.5.1 General... 4.5.2 Documentformat. 5 Field Encoding. 5.1 Field aspects. 5.1.1 General. 5.1.2 Semanticdatatype 5.1.3 Encoding. 5.1.4 Metadata... 5.1.5 Field presence 5.1.6 Defaultvalue 5.2 FIXdatatype summary 5.3 Commonfieldschemaattributes 5.3.1 General. 5.3.2 Inherited attributes. .8 5.3.3 Non-FIX types. 5.4 Integerencoding. .8 5.4.1 General.. 8 5.4.2 Primitivetype encodings. .8 5.4.3 Range attributes for integer fields 5.4.4 Byte order 5.4.5 Integerencodingspecifications. .9 5.4.6 Examples ofinteger fields. 9 5.5 Decimal encoding.. 5.5.1 General.. .10 5.5.2 Composite encodings .10 5.5.3 Range attributesfor decimal fields .10 5.5.4 Encodingspecificationsfordecimaltypes .11 5.5.5 Compositeencodingpadding 5.5.6 Examples ofdecimal fields. .11 5.6 Float encoding. 5.6.1 General. .11 5.6.2 Primitivetypes. 5.6.3 Null values. 12 IS0/IEC 2025-All rights reserved ili IS0/IEC25390:2025(en) 5.6.4 Byte order. 5.6.5 Float encoding specifications .12 5.6.6 Examples offloatingpointfields ..12 5.7 String encodings .12 5.7.1 General.. .12 5.7.2 Character 5.7.3 Fixed-length character array ..13 5.7.4 Variable-length string encoding. 5.7.5 Range attributes for string Length.. .14 5.7.6 Encodingspecifications forvariable-length string ..14 5.7.7 Example of a variable-length string field .15 5.8 Data encodings .15 5.8.1 General.. 5.8.2 Fixed-length data. ...15 5.8.3 Variable-length data encoding... 5.8.4 Range attributes forvariable-length data Length .16 5.8.5 Encodingspecifications for variable-length data ..16 .16 5.8.6 Example ofa data field 5.9 MonthYearencoding.. .16 5.9.1 General... 5.9.2 Compositeencodingpadding ..17 5.9.3 Encoding specifications forMonthYear 5.10 Date and timeencoding.. .17 5.10.1 General. .17 5.10.2 Epoch.. 17 5.10.3Time unit. .17 5.10.4 Encoding specifications for date and time. 5.10.5Examples ofdate/timefields. .18 5.11 Local date encoding. 5.12Local timeencoding. 19 5.12.1General... 5.12.2TZTimestampencoding 19 5.12.3Compositeencodingpadding .20 5.12.4 TZTimeOnly encoding... 5.12.5Compositeencodingpadding .20 5.13 Enumeration encoding. 5.13.1 General... .21 5.13.2 Primitive type encodings. .21 5.13.3 Value encoding .21 5.13.4Encodingspecificationofenumeration. .21 5.13.5Enumerationexamples.. 5.13.6Constantfieldofanenumerationvalue. ..2 5.13.7Boolean encoding.. 5.14 Multi-value choice encoding 23 5.14.1 General... ..23 5.14.2 Primitive type encodings. 23 5.14.3Value encoding.. 23 5.14.4 Encoding specification ofmulti-value choice. 5.14.5 Multi-value example... ...23 5.15 Field value validation. .24 6 Message Structure. 6.1 Message Framing. .24 6.1.1 General.. ..24 6.1.2SimpleOpenFramingHeader 24 6.2 SBE Message Encoding Header. .25 6.2.1 General..... 6.2.2 Messageheaderschema .25 6.2.3 Root block length 6.2.4 TemplateID. .26 IS0/IEC 2025-All rights reserved iv IS0/IEC25390:2025(en) 6.2.5 Schema ID .26 6.2.6 Schema version. 26 6.2.7 Number ofrepeatinggroups ..26 6.2.8 Number of varia