PayPal.Me. HTML Living Standard — Last Updated 23 August 2024 One-Page Version html.spec.whatwg.org Multipage Version /multipage Version for Web Devs /dev PDF Version /print.pdf Translations 日本語 • 简体中文 FAQ on GitHub Chat on Matrix Contribute on GitHub whatwg/html repository Commits on GitHub Snapshot as of this commit Twitter Updates @htmlstandard Open Issues filed on GitHub Open an Issue whatwg.org/newbug Tests web-platform-tests html/ Issues for Tests ongoing work Table of contents 1 Introduction 2 Common infrastructure 3 Semantics, structure, and APIs of HTML documents 4 The elements of HTML 5 Microdata 6 User interaction 7 Loading web pages 8 Web application APIs 9 Communication 10 Web workers 11 Worklets 12 Web storage 13 The HTML syntax 14 The XML syntax 15 Rendering 16 Obsolete features 17 IANA considerations Index References Acknowledgments Intellectual property rights Full table of contents 1 Introduction 1.1 Where does this specification fit? 1.2 Is this HTML5? 1.3 Background 1.4 Audience 1.5 Scope 1.6 History 1.7 Design notes 1.7.1 Serializability of script execution 1.7.2 Compliance with other specifications 1.7.3 Extensibility 1.8 HTML vs XML syntax 1.9 Structure of this specification 1.9.1 How to read this specification 1.9.2 Typographic conventions 1.10 A quick introduction to HTML 1.10.1 Writing secure applications with HTML 1.10.2 Common pitfalls to avoid when using the scripting APIs 1.10.3 How to catch mistakes when writing HTML: validators and conformance checkers 1.11 Conformance requirements for authors 1.11.1 Presentational markup 1.11.2 Syntax errors 1.11.3 Restrictions on content models and on attribute values 1.12 Suggested reading 2 Common infrastructure 2.1 Terminology 2.1.1 Parallelism 2.1.2 Resources 2.1.3 XML compatibility 2.1.4 DOM trees 2.1.5 Scripting 2.1.6 Plugins 2.1.7 Character encodings 2.1.8 Conformance classes 2.1.9 Dependencies 2.1.10 Extensibility 2.1.11 Interactions with XPath and XSLT 2.2 Policy-controlled features 2.3 Common microsyntaxes 2.3.1 Common parser idioms 2.3.2 Boolean attributes 2.3.3 Keywords and enumerated attributes 2.3.4 Numbers 2.3.4.1 Signed integers 2.3.4.2 Non-negative integers 2.3.4.3 Floating-point numbers 2.3.4.4 Percentages and lengths 2.3.4.5 Nonzero percentages and lengths 2.3.4.6 Lists of floating-point numbers 2.3.4.7 Lists of dimensions 2.3.5 Dates and times 2.3.5.1 Months 2.3.5.2 Dates 2.3.5.3 Yearless dates 2.3.5.4 Times 2.3.5.5 Local dates and times 2.3.5.6 Time zones 2.3.5.7 Global dates and times 2.3.5.8 Weeks 2.3.5.9 Durations 2.3.5.10 Vaguer moments in time 2.3.6 Colors 2.3.7 Space-separated tokens 2.3.8 Comma-separated tokens 2.3.9 References 2.3.10 Media queries 2.3.11 Unique internal values 2.4 URLs 2.4.1 Terminology 2.4.2 Parsing URLs 2.4.3 Dynamic changes to base URLs 2.5 Fetching resources 2.5.1 Terminology 2.5.2 Determining the type of a resource 2.5.3 Extracting character encodings from meta elements 2.5.4 CORS settings attributes 2.5.5 Referrer policy attributes 2.5.6 Nonce attributes 2.5.7 Lazy loading attributes 2.5.8 Blocking attributes 2.5.9 Fetch priority attributes 2.6 Common DOM interfaces 2.6.1 Reflecting content attributes in IDL attributes 2.6.2 Using reflect in specifications 2.6.3 Collections 2.6.3.1 The HTMLAllCollection interface 2.6.3.1.1 [[Call]] ( thisArgument, argumentsList ) 2.6.3.2 The HTMLFormControlsCollection interface 2.6.3.3 The HTMLOptionsCollection interface 2.6.4 The DOMStringList interface 2.7 Safe passing of structured data 2.7.1 Serializable objects 2.7.2 Transferable objects 2.7.3 StructuredSerializeInternal ( value, forStorage [ , memory ] ) 2.7.4 StructuredSerialize ( value ) 2.7.5 StructuredSerializeForStorage ( value ) 2.7.6 StructuredDeserialize ( serialized, targetRealm [ , memory ] ) 2.7.7 StructuredSerializeWithTransfer ( value, transferList ) 2.7.8 StructuredDeserializeWithTransfer ( serializeWithTransferResult, targetRealm ) 2.7.9 Performing serialization and transferring from other specifications 2.7.10 Structured cloning API 3 Semantics, structure, and APIs of HTML documents 3.1 Documents 3.1.1 The Document object 3.1.2 The DocumentOrShadowRoot interface 3.1.3 Resource metadata management 3.1.4 Reporting document loading status 3.1.5 Render-blocking mechanism 3.1.6 DOM tree accessors 3.2 Elements 3.2.1 Semantics 3.2.2 Elements in the DOM 3.2.3 HTML element constructors 3.2.4 Element definitions 3.2.4.1 Attributes 3.2.5 Content models 3.2.5.1 The "nothing" content model 3.2.5.2 Kinds of content 3.2.5.2.1 Metadata content 3.2.5.2.2 Flow content 3.2.5.2.3 Sectioning content 3.2.5.2.4 Heading content 3.2.5.2.5 Phrasing content 3.2.5.2.6 Embedded content 3.2.5.2.7 Interactive content 3.2.5.2.8 Palpable content 3.2.5.2.9 Script-supporting elements 3.2.5.3 Transparent content models 3.2.5.4 Paragraphs 3.2.6 Global attributes 3.2.6.1 The title attribute 3.2.6.2 The lang and xml:lang attributes 3.2.6.3 The translate attribute 3.2.6.4 The di
PayPal.Me. HTML Living Standard — Last Updated 23 August 2024 One-Page Version html.spec.whatwg.org Multipage Version /multipage Version for Web Devs /dev PDF Version /print.pdf Translations 日本語 • 简体中文 FAQ on GitHub Chat on Matrix Contribute on GitHub whatwg/html repository Commits on GitHub Snapshot as of this commit Twitter Updates @htmlstandard Open Issues filed on GitHub Open an Issue whatwg.org/newbug Tests web-platform-tests html/ Issues for Tests ongoing work Table of contents 1 Introduction 2 Common infrastructure 3 Semantics, structure, and APIs of HTML documents 4 The elements of HTML 5 Microdata 6 User interaction 7 Loading web pages 8 Web application APIs 9 Communication 10 Web workers 11 Worklets 12 Web storage 13 The HTML syntax 14 The XML syntax 15 Rendering 16 Obsolete features 17 IANA considerations Index References Acknowledgments Intellectual property rights Full table of contents 1 Introduction 1.1 Where does this specification fit? 1.2 Is this HTML5? 1.3 Background 1.4 Audience 1.5 Scope 1.6 History 1.7 Design notes 1.7.1 Serializability of script execution 1.7.2 Compliance with other specifications 1.7.3 Extensibility 1.8 HTML vs XML syntax 1.9 Structure of this specification 1.9.1 How to read this specification 1.9.2 Typographic conventions 1.10 A quick introduction to HTML 1.10.1 Writing secure applications with HTML 1.10.2 Common pitfalls to avoid when using the scripting APIs 1.10.3 How to catch mistakes when writing HTML: validators and conformance checkers 1.11 Conformance requirements for authors 1.11.1 Presentational markup 1.11.2 Syntax errors 1.11.3 Restrictions on content models and on attribute values 1.12 Suggested reading 2 Common infrastructure 2.1 Terminology 2.1.1 Parallelism 2.1.2 Resources 2.1.3 XML compatibility 2.1.4 DOM trees 2.1.5 Scripting 2.1.6 Plugins 2.1.7 Character encodings 2.1.8 Conformance classes 2.1.9 Dependencies 2.1.10 Extensibility 2.1.11 Interactions with XPath and XSLT 2.2 Policy-controlled features 2.3 Common microsyntaxes 2.3.1 Common parser idioms 2.3.2 Boolean attributes 2.3.3 Keywords and enumerated attributes 2.3.4 Numbers 2.3.4.1 Signed integers 2.3.4.2 Non-negative integers 2.3.4.3 Floating-point numbers 2.3.4.4 Percentages and lengths 2.3.4.5 Nonzero percentages and lengths 2.3.4.6 Lists of floating-point numbers 2.3.4.7 Lists of dimensions 2.3.5 Dates and times 2.3.5.1 Months 2.3.5.2 Dates 2.3.5.3 Yearless dates 2.3.5.4 Times 2.3.5.5 Local dates and times 2.3.5.6 Time zones 2.3.5.7 Global dates and times 2.3.5.8 Weeks 2.3.5.9 Durations 2.3.5.10 Vaguer moments in time 2.3.6 Colors 2.3.7 Space-separated tokens 2.3.8 Comma-separated tokens 2.3.9 References 2.3.10 Media queries 2.3.11 Unique internal values 2.4 URLs 2.4.1 Terminology 2.4.2 Parsing URLs 2.4.3 Dynamic changes to base URLs 2.5 Fetching resources 2.5.1 Terminology 2.5.2 Determining the type of a resource 2.5.3 Extracting character encodings from meta elements 2.5.4 CORS settings attributes 2.5.5 Referrer policy attributes 2.5.6 Nonce attributes 2.5.7 Lazy loading attributes 2.5.8 Blocking attributes 2.5.9 Fetch priority attributes 2.6 Common DOM interfaces 2.6.1 Reflecting content attributes in IDL attributes 2.6.2 Using reflect in specifications 2.6.3 Collections 2.6.3.1 The HTMLAllCollection interface 2.6.3.1.1 [[Call]] ( thisArgument, argumentsList ) 2.6.3.2 The HTMLFormControlsCollection interface 2.6.3.3 The HTMLOptionsCollection interface 2.6.4 The DOMStringList interface 2.7 Safe passing of structured data 2.7.1 Serializable objects 2.7.2 Transferable objects 2.7.3 StructuredSerializeInternal ( value, forStorage [ , memory ] ) 2.7.4 StructuredSerialize ( value ) 2.7.5 StructuredSerializeForStorage ( value ) 2.7.6 StructuredDeserialize ( serialized, targetRealm [ , memory ] ) 2.7.7 StructuredSerializeWithTransfer ( value, transferList ) 2.7.8 StructuredDeserializeWithTransfer ( serializeWithTransferResult, targetRealm ) 2.7.9 Performing serialization and transferring from other specifications 2.7.10 Structured cloning API 3 Semantics, structure, and APIs of HTML documents 3.1 Documents 3.1.1 The Document object 3.1.2 The DocumentOrShadowRoot interface 3.1.3 Resource metadata management 3.1.4 Reporting document loading status 3.1.5 Render-blocking mechanism 3.1.6 DOM tree accessors 3.2 Elements 3.2.1 Semantics 3.2.2 Elements in the DOM 3.2.3 HTML element constructors 3.2.4 Element definitions 3.2.4.1 Attributes 3.2.5 Content models 3.2.5.1 The "nothing" content model 3.2.5.2 Kinds of content 3.2.5.2.1 Metadata content 3.2.5.2.2 Flow content 3.2.5.2.3 Sectioning content 3.2.5.2.4 Heading content 3.2.5.2.5 Phrasing content 3.2.5.2.6 Embedded content 3.2.5.2.7 Interactive content 3.2.5.2.8 Palpable content 3.2.5.2.9 Script-supporting elements 3.2.5.3 Transparent content models 3.2.5.4 Paragraphs 3.2.6 Global attributes 3.2.6.1 The title attribute 3.2.6.2 The lang and xml:lang attributes 3.2.6.3 The translate attribute 3.2.6.4 The di