Definition of "local attribute"

A local attribute is firmly associated with a specific element type and therefore is defined to be coded only on that element. The name of a local attribute is allocated from an namespace partition for that specific element's attribute names and is only associated with a namespace indirectly through that element. A local attribute with the same name on another element is a distinctly different type of attribute.

Contrast with global attribute and the HTML common attributes, which are global attributes in HTML documents.