version 

- specifies the version used in the XML document (1.0)

encoding

- defines the character encoding used in the XML document (UTF-8)

standalone

- if the value is

yes

it means there is no external declaration required to parse the document (yes)

XML references allow us to have symbols in XML text, that are not allowed to be included directly. References begin with the symbol

&

which is a reserved character and end with the symbol

;

XML has two types of references: ... 1.

Entity Reference

− which contains a name between the start and the end delimiters. For example

&

where amp is name. The name refers to

&

symbol. ... 2.

Character Reference

− contains reference, such as

A

contains a hash mark

#

followed by a number. The number refers to the Unicode code of a character. In this case, 65 refers to alphabet

A

Some characters are are not allowed in XML text because they are reserved by the XML itself. Hence, they cannot be used directly. If we need to include them in text, some replacement-entities are used. These symbols are:

<

- less than -

<

>

- greater than -

>

'

- ampersand -

&

"

- apostrophe -

'

&

- quotation mark -

"