They may appear in any order. Attribute names are always case-insensitive.
Attribute values are generally case-insensitive.
The other values specify vertical alignment of text relative to the frame on the same line. Displays no border. This attribute explicitly specifies the height of the frame in pixels. It can be used to speed up display of the document being downloaded so it can pre-render the document without the frame while the frame downloads. Let the browser decide if a scrollbar is necessary.