In a start-tag, white space and attributes are allowed between the element name and the closing delimiter. An attribute specification typically consists of an attribute name, an equal sign, and a value, though some attribute specifications may be just a name token. White space is allowed around the equal sign.
The value of the attribute may be either:
In this example, <img> is the element name, src is the attribute name, and `http://host/dir/file.gif' is the attribute value:
A useful technique for computing an attribute value literal for a given string is to replace each quote and white space character by an entity reference or numeric character reference as follows:
ENTITY NUMERIC CHARACTER REFERENCE CHAR REF CHARACTER DESCRIPTION --------- ---------- ----------- --------------------- HT 	 Tab LF Line Feed CR Carriage Return SP   Space " " " Quotation mark & & & Ampersand
<IMG SRC="image.jpg" alt="First "real" example">
The `NAMELEN' parameter in the SGML declaration (9.5, "SGML Declaration for HTML") limits the length of an attribute value to 1024 characters.
Attributes such as ISMAP and COMPACT may be written using a minimized syntax (see 18.104.22.168 "Omitted Attribute Name" in [SGML]). The markup:
can be written using a minimized syntax: