The value must conform to BCP 47. If the value is a
private use code (i.e., starts with x- or contains
-x-) it should, and if not it may, match the value
of an ident attribute of a language element
supplied in the TEI Header of the current document.
rend
(rendition) indicates how the element in question was rendered or
presented in the source text.
any string of characters; if the typographic rendition
of a text is to be systematically recorded, a systematic set of
values for the rend attribute should be
defined.
<headrend="align(center) case(allcaps)"> <lb/>To The <lb/>Duchesse <lb/>of <lb/>Newcastle, <lb/>On Her <lb/> <hirend="case(mixed)">New Blazing-World</hi>.
</head>
rendition
points to a description of the rendering or
presentation used for this element in the source text.