element element-qualifier* (is | isnt) (element-name | element-name-list)

An element test that succeeds if the element being tested is identified by one of the specified names.

If no element qualifiers are present, the test applies to the current element.

The test allows the programmer to specify either a single element name or a parenthesized list of element-names, separated by or or "|", instead of a single element name.