IEC_62298-4-2005.pdf

INTERNATIONAL STANDARD IEC62298-4 First edition2005-10 TeleWeb application Part 4:Hyperteletext profile Reference number IEC 62298-4:2005(E)LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.Publication numbering As from 1 January 1997 all IEC publications are issued with a designation in the 60000 series.For example,IEC 34-1 is now referred to as IEC 60034-1.Consolidated editions The IEC is now publishing consolidated versions of its publications.For example,edition numbers 1.0,1.1 and 1.2 refer,respectively,to the base publication,the base publication incorporating amendment 1 and the base publication incorporating amendments 1 and 2.Further information on IEC publications The technical content of IEC publications is kept under constant review by the IEC,thus ensuring that the content reflects current technology.Information relating to this publication,including its validity,is available in the IEC Catalogue of publications(see below)in addition to new editions,amendments and corrigenda.Information on the subjects under consideration and work in progress undertaken by the technical committee which has prepared this publication,as well as the list of publications issued,is also available from the following:IEC Web Site(www.iec.ch)Catalogue of IEC publications The on-line catalogue on the IEC web site(www.iec.ch/searchpub)enables you to search by a variety of criteria including text searches,technical committees and date of publication.On-line information is also available on recently issued publications,withdrawn and replaced publications,as well as corrigenda.IEC Just Published This summary of recently issued publications(www.iec.ch/online_news/justpub)is also available by email.Please contact the Customer Service Centre(see below)for further information.Customer Service Centre If you have any questions regarding this publication or need further assistance,please contact the Customer Service Centre:Email:custserviec.ch Tel:+41 22 919 02 11 Fax:+41 22 919 03 00 LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.INTERNATIONAL STANDARD IEC62298-4 First edition2005-10 TeleWeb application Part 4:Hyperteletext profile IEC 2005 Copyright-all rights reserved 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 the publisher.International Electrotechnical Commission,3,rue de Varemb,PO Box 131,CH-1211 Geneva 20,SwitzerlandTelephone:+41 22 919 02 11 Telefax:+41 22 919 03 00 E-mail:inmailiec.ch Web:www.iec.ch W For price,see current cataloguePRICE CODE Commission Electrotechnique InternationaleInternational Electrotechnical Commission LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.2 62298-4 IEC:2005(E)CONTENTS FOREWORD.3 INTRODUCTION.5 1 Scope.6 2 Normative references.6 3 Terms,definitions and abbreviations.7 3.1 Terms and definitions.7 3.2 Abbreviations.7 4 Mandatory Superteletext profile features.8 4.1 Font issues.8 4.2 Dithering.8 4.3 TeleWeb EPG.8 4.4 Cross-linking between services.8 4.5 Memory requirements.8 5 General display-related extensions.9 5.1 Downloadable fonts.9 5.2 Support for non-Latin alphabets.9 5.3 Page size and page scrolling.9 6 Hypertext extensions.9 6.1 HTML frames.10 6.2 Forms.16 6.3 Internationalization.25 6.4 tag.26 6.5 tag.27 7 User profiles.29 8 ISP interface.29 8.1 The ISP special function.29 8.2 Network congestion control.31 9 Device ID(OPTIONAL).33 10 Cross-linking and context-switching.33 10.1 Additional URI schemes.33 11 Audio clips(OPTIONAL).33 12 Style sheets.34 13 Scripting.34 13.1 ECMAScript.34 13.2 tag.35 13.3 Events.35 13.4 Document object model(DOM).35 14 Additional content types.35 14.1 Graphic files.35 14.2 Text files.35 Annex A(informative)Security considerations.36 LICENSED TO MECON Limited.-RANCHI/BANGALOREFOR INTERNAL USE AT THIS LOCATION ONLY,SUPPLIED BY BOOK SUPPLY BUREAU.62298-4 IEC:2005(E)3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ TELEWEB APPLICATION Part 4:Hyperteletext profile FOREWORD 1)The International Electrotechnical Commission(IEC)is a worldwide organization for standardization comprising all national electrotechnical committees(IEC National Committees).The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields.To this end and in addition to other activities,IEC publishes International Standards,Technical Specifications,Technical Reports,Publicly Available Specifications(PAS)and Guides(hereafter referred to as“IEC Publication(s)”).Their preparation is entrusted to technical committees;any IEC National Committee interested in the subject dealt with may participate in this preparatory work.International,governmental and non-governmental organizations liaising wi