There is a distinct use of <label> to record the marginal headings so common in older books, exemplified in the 3rd example
at http://www.tei-c.org/release/doc/tei-p5-doc/en/html/CO.html#CONONO. There, the marginal placement is marked by @rend.
This bothers me, as the position in the margin is rather structural, indicating it is a floating object, not just a rendition. I therefore
suggest that we add @place to <label>, comparable to <note>.
I also suggest that this extended use of <label> makes it a good candidate for a @type attribute. For example, to distinguish a set of <label>s which
mark "years since the founding of Rome" from a set which provide a little heading
There are many many examples in TCP EEBO of the marginal material.