For that reason it is easy to define and specify. An element consists of an opening label, text, and a closing label. A special case of an element is an empty element. This element does not have any associated text. The attribute label, in this case 'type' follows the same rules as an element label.
Case is significant.
The equal sign is required. The text string description must be enclosed in quotes. The difference between elements and attributes is often subtle. One analogy is elements are nouns and attributes are adjectives. That analogy works up to a point.