preface

Internet Explorer 5.5 introduced the concept of document schema, which is implemented by using document type (DOCTYPE) toggles.

The document model

Document mode is mainly divided into hybrid mode and standard mode, while standard mode can be divided into standard mode, quasi-standard mode and super standard mode (standard mode and quasi-standard mode are very close, their differences are almost negligible). The specific distinction is shown as follows:

The standard model

This can be enabled by any of the following types:

HTML 4.01 strict

<! -- HTML 4.01 Strict --> <! DOCTYPE HTML PUBLIC"- / / / / W3C DTD HTML 4.01 / / EN"
"http://www.3c.org/TR/html4/strict.dtd">
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XHTML 1.0 is strict

<! -- XHTML 1.0 strict --> <! DOCTYPE HTML PUBLIC"- / / / / W3C DTD XHTML 1.0 Strict / / EN"
"http://www.3c.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
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HTML 5

<! -- HTML 5 --> <! DOCTYPE HTML>Copy the code

Quasi standard mode

This can be triggered by the use of transitional or frameset, as follows:

HTML 4.01 transition type

<! -- HTML 4.01 Transition --> <! DOCTYPE HTML PUBLIC"- / / / / W3C DTD HTML 4.01 Transitional / / EN"
"http://www.3c.org/TR/html4/DTD/loose.dtd">
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HTML 4.01 frameset type

<! HTML 4.01 frameset type --> <! DOCTYPE HTML PUBLIC"- / / / / W3C Frameset DTD HTML 4.01 / / EN"
"http://www.3c.org/TR/html4/frameset.dtd">
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XHTML 1.0 is transitional

<! -- XHTML 1.0 transition --> <! DOCTYPE HTML PUBLIC"- / / / / W3C DTD XHTML 1.0 Transitional / / EN"
"http://www.3c.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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XHTML 1.0 frameset type

<! -- XHTML 1.0 frameset --> <! DOCTYPE HTML PUBLIC"- / / / / W3C DTD XHTML 1.0 Frameset / / EN"
"http://www.3c.org/TR/xhtml1/DTD/xhtml1-frameset.dtd">
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Super Standard mode

IE8 default mode, but its default mode can be turned off by:

<meta http-equiv="X-UA-Compatible" content="IE=7" />
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IE is used to specify which version of the rendering engine to use to render pages, with the goal of backward compatibility with sites and pages designed specifically for older versions of IE.

reference

JavaScript Advanced Programming

summary

This article focuses on several HTML document modes and their differences (see the illustration).

If you have any questions, please point out.