HTML Extremes

These are a little tricky, and might break some quick-and-dirty implementations. But they must be parsed correctly by all minimally conforming WWW implementations.

Some of these constructs are markup errors which are not handled correctly by various browsers.

These constructs are not recommended.

Text Elements

Tags

The tags for this element have spaces in them.

Just in case it missed the H3 close tag:

Names

A name should be a letter followed by letter and/or numbers. Case is not significant.

h4 with different case in start and end tags

Normal Text Content

Delimiter Recognition

Character reference: '&#SPACE;' and È and '&#foo;'. The last one is an error. And character as data: &, and as markup: &.

And-hash as data: &# and as markup &#.

Less-thans as data: < <1 <-)

Less-than-slash as data: greater-than (pretty much always data): > abc> 0>

comment: The sample implementation groks.

comment w/space between -- and >: tags are fine! & as long as it's not followed by a letter or '#', it's fine! &# is even ok, unless it's followed by a letter or a number. Line breaks are significant, and characters are rendered in a fixed-width font to preserve horizontal formatting.

This is literal text with tabs. THESE words should line up under THESE words.

Other Elements

TITLE

The TITLE can actually be as long as you like. It can have all the '>' you want too. It just can't have the ETAGO delimiter-in-context, that is "</" followed by a letter. '&' should be avoided, so that entities can be treated uniformly throughout HTML.

Anchors

name implied

HREF implied

HREF before name

spaces around '='

single quoted value

character references and entity references in attribute value literal

ID already in use