The XML declaration is a processing instruction that identifies the document as being XML. All XML documents should begin with an XML declaration.

<?xml
 version="version_number"
 encoding="encoding_declaration"
 standalone="standalone_status" ?>

<?xml version="1.0" encoding="UTF-8" standalone="no" ?>

Rules:

• If the XML declaration is included, it must be situated at the first position of the first line in the XML document.
• If the XML declaration is included, it must contain the version number attribute.
• If all of the attributes are declared in an XML declaration, they must be placed in the order shown above.
• If any elements, attributes, or entities are used in the XML document that are referenced or defined in an external DTD, standalone="no" must be included.
• The XML declaration must be in lower case (except for the encoding declarations).

Note:

• The XML declaration has no closing tag, that is </?xml>.

The following table shows a list of the possible attributes that may be used in the XML declaration.

Attribute Name:	Possible Attribute Value:	Attribute Description:
version	1.0	Specifies the version of the XML standard that the XML document conforms to. The version attribute must be included if the XML declaration is declared.
encoding	UTF-8, UTF-16, ISO-10646-UCS-2, ISO-10646-UCS-4, ISO-8859-1 to ISO-8859-9, ISO-2022-JP, Shift_JIS, EUC-JP	These are the encoding names of the most common character sets in use today. For a full list of encodings check the IANA's website.
standalone	yes, no	Use 'yes' if the XML document has an internal DTD. Use 'no' if the XML document is linked to an external DTD, or any external entity references.

XML Guide TOC

XML Declaration
DOCTYPE Declaration & DTDs
ELEMENT Type Declaration
ATTLIST Declaration
ENTITY Declaration
NOTATION Declaration
CDATA Section
Processing Instruction
Conditional Section
Comments

Glossary