XHTML

HTML allows authors to add hypertext of the complexity of the current HTML language (at Sept. 1995 this is HTML 2.0). Authors are assumed to be familiar with HTML and the DTD will not be documented here. There are, however a few important differences:

The content model is strict HTML2.0 without:
- FORMS
- the "HTML.deprecated" elements
- <HEAD> head-content </HEAD>
In other words, it is an allowable %body.content without FORMS.
There are three extra attributes (for XHTML) (see below) to allow heads of links, and description of the content and purpose of the HTML container.
Strict XML is required. The main differences from 'normal' HTML are:
- All closing tags must be included (except for EMPTY elements such as BR.) (The most commonly omitted ETAGs in ordinary HTML are LI and P.)
- paragraphs must start with a <P> and end with a </P> tag.
- Attributes must obey SGML rules (quotes must be used for attribute values and must be balanced.)
- PRE is not used.
- a single set of <BODY> ... </BODY> tags are required.

Content Model

(See above).

Content

body -- Container for main body of HTML document (HTML 2.0)

ATTRIBUTES
CONTENT DECLARATION

Tag Minimization: Open Tag: REQUIRED
Close Tag: REQUIRED

Parent Elements

admin -- Administrivia.
atoms -- A generic container for atomic coordinates and properties
bib -- A bibliographic entry.
bonds -- A generic container for bonds and their properties
cml -- A toplevel DTD encompassing HTML 2.0, TecML and MOL.
cryst -- Crystallographic data, especially unit cell and symmetry.
feature -- Features of macromolecules (e.g. SITE, MUTATION).
figure -- A figure, possibly in encoded binary.
formula -- Chemical formula.
mol -- Toplevel container for molecular information.
person -- A person and their attributes.
reaction
relation -- Describes relationship between objects, including hyperlinks. Experimental at present.
sequence -- Represents a macromolecular sequence.
symmetry -- Molecular symmetry.
tecml -- A toplevel container for the TecML DTD.
termentry -- A terminological entry

Top Elements
All Elements
Tree

cml DTD