Webmaster in a Nutshell, Third Edition

Name

<?xml ...?>

Synopsis

Although they are not required to, XML documents typically begin with an XML declaration, which must start with the characters <?xml and end with the characters ?>. Attributes include:

Attributes

version

The version attribute specifies the correct version of XML required to process the document, which is currently 1.0. This attribute cannot be omitted.

encoding

The encoding attribute specifies the character encoding used in the document (e.g., UTF-8 or iso-8859-1). UTF-8 and UTF-16 are the only encodings that an XML processor is required to handle. This attribute is optional.

standalone

The optional standalone attribute specifies whether an external DTD is required to parse the document. The value must be either yes or no (the default). If the value is no or the attribute is not present, a DTD must be declared with an XML <!DOCTYPE> instruction. If it is yes, no external DTD is required.

For example:

<?xml version="1.0"?>
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<?xml version="number"
[encoding="encoding"]
[standalone="yes|no"] ?>