What is an option inside a tag called in XML?

Question

Take this piece of XML:

<foo bar='biz'></foo>

What is the bar value called? This seems like it should be obvious, but I realized that even with the amount of XML and HTML I have used I do not know what such values are formally reffered to as. Any help is appreciated.

Answer 1

The construct bar='biz' as a whole is called attribute specification (often informally attribute for short), and the 'biz' part is attribute value (it is not clear from the question which one you mean). Ref. XML 1.0 spec.

Answer 2

It is called attribute.

Google is usually best for such answers: https://www.google.co.uk/search?q=xml+attributes