Most often, the purpose of data validation is to ensure correct input to a computer application.Validation can be defined by many different methods, and deployed in many different ways.
As mentioned in the HTML 4 Recommendation's note about specifying non-HTML data in element content, end tags are recognized within SCRIPT elements, but other kinds of markup--such as start tags and comments--are not.
This is an unintuitive quirk of , authors must also take care when using start tags within a script element.
For details, see the Script and Style elements section of the XHTML 1.0 Recommendation as well as the HTML compatibility guideline for embedded scripts.
Another common error occurs when including a This example generates an error for "unknown entity section" because the "&" is assumed to begin an entity reference.
Browsers often recover safely from this kind of error, but real problems do occur in some cases.
In this example, many browsers correctly convert ©=3 to ©=3, which may cause the link to fail.Since 〈 is the entity for the left-pointing angle bracket, some browsers also convert &lang=en to 〈=en.And one old browser even finds the entity §, converting §ion=2 to §ion=2.To avoid problems with both validators and browsers, always use & in place of & when writing If you receive the error "Missing a required sub-element of HEAD", check that you have included the TITLE element in the HEAD.The TITLE element is required in all HTML documents.In XHTML, unlike HTML, element and attribute names must be all lowercase.Tags: Adult Dating, affair dating, sex dating