Each element in this specification has a definition that includes the following information:
A list of categories to which the element belongs. These are used when defining the content models for each element.
A non-normative description of where the element can be used. This information is redundant with the content models of elements that allow this one as a child, and is provided only as a convenience.
For simplicity, only the most specific expectations are listed. For example, an element that is both flow content and phrasing content can be used anywhere that either flow content or phrasing content is expected, but since anywhere that flow content is expected, phrasing content is also expected (since all phrasing content is flow content), only "where phrasing content is expected" will be listed.
A normative description of what content must be included as children and descendants of the element.
A normative list of attributes that may be specified on the element (except where otherwise disallowed).
A normative definition of a DOM interface that such elements must implement.
This is then followed by a description of what the element represents, along with any additional normative conformance criteria that may apply to authors. Examples are sometimes also included.
Except where otherwise specified, attributes on HTML elements may have any string value, including the empty string. Except where explicitly stated, there is no restriction on what text can be specified in such attributes.