,

,

, etc.) is deprecated in favor of the individual element . Levels of headings might instead exist as indicated per nested

elements both by having their have running. A presentational elements , & , however allowed around XHTML One.x (potentially Strict), is scatty from either XHTML Two.Cypher. A exclusively presentational elements remaining is & for superior & inferior severally.

Others in the XHTML family
XHTML Basic: A favorite "light" versiin of XHTML for hardware which just can't have a to the full XHTML placed, primarily utilized on handhelds like mobile phones. This is the designed replacement for WML and C-HTML. XHTML Mobile Profile: Based on XHTML Basic, this OMA ([http://www.openmobilealliance.org/ Open Mobile Alliance]) effort targets hand phones specifically by adding mobile phone-specific elements to XHTML Basic.

Validating XHTML documents
An XHTML document that conforms to the XHTML specification is said to exist as the valid document. Around a hone globe, completely browsers would watch the web standards & valid documents would predictably render in each web browser & platform. Although validating the XHTML doesn't assure cross-web browser compatibility, it is recommended. a document may be checked for validity by owning the W3C Markup Validation Service.

DOCTYPEs
For the document to validate, it must contain the Document Type Declaration, or DOCTYPE. The DOCTYPE declares to the web browser what Document Type Definition (DTD) the document conforms to. a Document Nature and severity Declaration should become set at the super beginning of an XHTML document. Which are actually a usual XHTML Document Nature and severity Declarations:

;XHTML Unity.Nought Strict ;XHTML Ace.Cipher Transitional ;XHTML Unity.Cipher Frameset ;XHTML One.1 A system identifier, which in these examples is the URL that begins with "http", require just point to a copy of a DTD to utilise in case the validator just can't retain a single according to the public identifier (the more quoted string). It doesn't want to become a specific Address that is within these examples; as a matter of fact, authors come encouraged to have local copies of the DTD files whilst conceivable. A public identifier, notwithstanding, must become character-for-character a equivalent when in the examples.

Character encoding may be specified at the beginning of an XHTML document in the XML declaration & in the meta http-equiv element. (In case an XML document lacks encryption specification, an XML parser assumes that the encryption is UTF-8 or even UTF-16, unless a encoding has already been determined by a higher protocol.)

Common errors
Occasionally of the usual errors inside XHTML come:

Not closing empty elements (elements forgoing closing tags) Incorrect:
Correct:
Not closing non-empty elements Incorrect:

This occurs as paragraph.

This is an additional paragraph. Correct:

This occurs as paragraph.

This is a second paragraph.

Improperly incubation elements (elements must exist as closed around reverse choose) Incorrect: This is a bit of text. Correct: This is occasionally text. Not specifying alternate text for images (using the alt attribute, which aids produce web sites accessible for gear that don't batch images or even screen-readers for the blind) Incorrect: Correct: Putting text directly inside a body of the document (this is non an error in XHTML One.Nought Transitional) Incorrect: Welcome to our report. Correct:

Welcome to the report.

Nesting prevent-level elements inside inline elements Incorrect:

Introduction

Correct:

Introduction

Not putting quotation marks in the area of attribute values Incorrect: