The <gi> element "contains the name (generic identifier) of an element".
The <att> element "contains the name of an attribute appearing within running text".
The name of an attribute and the name of an element are, of course, described by the W3C datatype xs:Name, which in P5 is used by the data.name datatype. So it would make sense that the content model of <gi> and <att> would be 1 occurence of data.name. But in fact, the content model is text.