In XHTML, all tags must be lowercase. The tongue cannot be interspersed with uppercase and lowercase, nor can it be all uppercase. Examples are as follows.
...
...< ;/div> tags, etc., when a tag appears, there must be a corresponding closing tag, both are indispensable, just like parentheses in any programming language.
Error: Hello everyone
is really good
Correct:
Hello everyone
is really good
Summary:
The order of tags must be correct. Tags are from outside to inside, covered layer by layer, so assuming you write div first and then h1, at the end you must write h1 first and then div. Just remember the principle of "first in, last out", the label that pops up first should end last.
error:
hello
Correct:
csdn
All attributes must use double quotes
In XHTML 1.0, it is stipulated that even single quotes cannot be used, so double quotes must be used throughout.
error：
csdn
Correct:
csdn
The use of target="_blank" is not allowed
The target attribute is completely prohibited starting from XHTML1.1. If you want to have the function of opening a new window, you must rewrite it as rel="external" and use JavaScript to achieve this effect. .
error:
csdn Correct:
csdnstick your tongue out
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