Usually elements are used to capture the data however attributes can be to capture the metadata (data about data – something that provides additional information about the data) ie the data which might not be used to display but can be used for search or other such features.There is no rule as such that says something should be an attribute or a element. I recommend to avoid it 
Some of the problems with using attributes are:
- attributes cannot contain multiple values (elements can)
- attributes cannot contain tree structures (elements can)
- attributes are not easily expandable (for future changes)
Attributes are difficult to read and maintain. Use elements for data. Use attributes for information that is not relevant to the data.
The following three XML documents contain exactly the same information:
A date attribute is used in the first example:
<note date=”10/01/2008″>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don’t forget me this weekend!</body>
</note>
A date element is used in the second example:
<note>
<date>10/01/2008</date>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don’t forget me this weekend!</body>
</note>
An expanded date element is used in the third: Preferred :
<note>
<date>
<day>10</day>
<month>01</month>
<year>2008</year>
</date>
<to>Tove</to>
<from>Jani</from>
<heading>Reminder</heading>
<body>Don’t forget me this weekend!</body>
</note>
