Internet Explorer 8 Compatibility Test Suites.

Quirks DTD pages in IE 8.

Check paddings & pseudo class. (O)=Right view in IE8. (X)=Broken view in IE8.

1. Quirks DTD & No Compatible Meta Tag (O) | Standard DTD & No Compatible Meta Tag (X)
2. Quirks DTD & IE=5 (O)
3. Quirks DTD & IE=7 (X)
4. Quirks DTD & IE=EmulateIE7 (O)
5. Quirks DTD & IE=8 (X)
6. Quirks DTD & IE=EmulateIE8 (O)
7. Quirks DTD & IE=Edge (X)

Standard DTD pages in IE 8.

Check paddings & pseudo class. (O)=Right view in IE8. (X)=Broken view in IE8.

1. Standard DTD Optimized IE 5 (X)
2. Standard DTD Optimized IE 5 & IE=5 (O)
3. Standard DTD Optimized IE 5/6 (X)
4. Standard DTD Optimized IE 5/6/7 (X)
5. Standard DTD Optimized IE 5/6/7 & IE=7 (O)

Internet Explorer 8 has three different layout modes.

• Quirks : backwards compatibility with Internet Explorer 5 rendering behavior.
• Internet Explorer 7 Standards : backwards compatibility with Internet Explorer 7 JavaScript and layout behavior.
• Internet Explorer 8 Standards : latest features, including the CSS 2.1-compliant layout engine and DOM/HTML breaking changes.

Implement X-UA-Compatible Tag.

• <meta http-equiv="X-UA-Compatible" content="IE=5" /> : Always use IE 5 quirks mode even though site has standards doctype.
• <meta http-equiv="X-UA-Compatible" content="IE=7" /> : Always use IE 7 standards mode even though site has quirks doctype.
• <meta http-equiv="X-UA-Compatible" content="IE=EmulageIE7" /> : Display in IE 7 standards mode unless site has quirks doctype.
• <meta http-equiv="X-UA-Compatible" content="IE=8" /> : Always use IE 8 standards mode even though site has quirks doctype.
• <meta http-equiv="X-UA-Compatible" content="IE=EmulageIE8" /> : Display in IE 8 standards mode unless site has quirks doctype.
• <meta http-equiv="X-UA-Compatible" content="IE=edge" /> : Display in latest mode. In the IE 9 release, this is equivalent to 'IE=9'.

References

• Internet Explorer 8 Readiness Toolkit (en)
• Internet Explorer 8 Readiness Toolkit (ko)