ISO/IEC International Standard ISO/IEC 10646 Final Draft International Standard Information technology – Universal Coded Character Set (UCS) Technologie de l‘information – Jeu universel de caractères codés (JUC) Second edition, 2011 \fdis10646.docx ISO/IEC 10646:2011 (E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF- creation parameters were optimized for 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. © ISO/IEC 2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the ad- dress below or ISO's member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail [email protected] Web www.iso.ch Printed in Switzerland 2 © ISO/IEC 2011 – All rights reserved ISO/IEC 10646:2011 (E) CONTENTS Foreword................................................................................................................................................ 13 Introduction ............................................................................................................................................ 14 1 Scope ............................................................................................................................................. 15 2 Conformance .................................................................................................................................. 15 2.1 General ................................................................................................................................ 15 2.2 Conformance of information interchange ............................................................................. 15 2.3 Conformance of devices ...................................................................................................... 16 3 Normative references ..................................................................................................................... 16 4 Terms and definitions ..................................................................................................................... 17 5 General structure of the UCS ......................................................................................................... 23 6 Basic structure and nomenclature .................................................................................................. 23 6.1 Structure ............................................................................................................................... 23 6.2 Coding of characters ............................................................................................................ 25 6.3 Types of code points ............................................................................................................ 25 6.4 Naming of characters ........................................................................................................... 26 6.5 Short identifiers for code points (UIDs) ................................................................................ 26 6.6 UCS Sequence Identifiers .................................................................................................... 27 6.7 Octet sequence identifiers ................................................................................................... 27 7 Revision and updating of the UCS ................................................................................................. 28 8 Subsets ........................................................................................................................................... 28 8.1 Limited subset ...................................................................................................................... 28 8.2 Selected subset .................................................................................................................... 28 9 UCS encoding forms ...................................................................................................................... 28 9.1 UTF-8 ................................................................................................................................... 28 9.2 UTF-16 ................................................................................................................................. 30 9.3 UTF-32 (UCS-4) ................................................................................................................... 31 10 UCS Encoding schemes ................................................................................................................ 31 10.1 UTF-8 ................................................................................................................................... 31 10.2 UTF-16BE ............................................................................................................................ 31 10.3 UTF-16LE ............................................................................................................................. 31 10.4 UTF-16 ................................................................................................................................. 31 10.5 UTF-32BE ............................................................................................................................ 32 10.6 UTF-32LE ............................................................................................................................. 32 10.7 UTF-32 ................................................................................................................................. 32 11 Use of control functions with the UCS ............................................................................................ 32 12 Declaration of identification of features .......................................................................................... 33 12.1 Purpose and context of identification ................................................................................... 33 12.2 Identification of a UCS encoding form ................................................................................. 34 12.3 Identification of subsets of graphic characters ..................................................................... 34 12.4 Identification of control function set...................................................................................... 34 12.5 Identification of the coding system of ISO/IEC 2022 ........................................................... 35 13 Structure of the code charts and lists ............................................................................................. 35 © ISO/IEC 2011 – All rights reserved 3 ISO/IEC 10646:2011 (E) 14 Block and collection names ............................................................................................................ 36 14.1 Block names ......................................................................................................................... 36 14.2 Collection names .................................................................................................................. 36 15 Mirrored characters in bidirectional context ................................................................................... 36 15.1 Mirrored characters .............................................................................................................. 36 15.2 Directionality of bidirectional text ......................................................................................... 36 16 Special characters .......................................................................................................................... 37 16.1 Space characters ................................................................................................................. 37 16.2 Currency symbols ................................................................................................................ 37 16.3 Format Characters ............................................................................................................... 37 16.4 Ideographic description characters ...................................................................................... 38 16.5 Variation selectors and variation sequences ....................................................................... 38 17 Presentation forms of characters ................................................................................................... 41 18 Compatibility characters ................................................................................................................