They may appear in any order. Attribute names are always case-insensitive.
Attribute values are generally case-insensitive.
The standard HTML color specification methods. If the system that is viewing the document does not have the font typeface specified by this attribute then the browser default is used. To ease portability, multiple typefaces can be specified in the attribute value separated by commas. It will check for availability starting from the style name on the left, working its way right. Comma separated list of font names.