[whatwg] [WA1] The a element could be empty

[S. Mike Dierken]

> What does it mean to link to an element in a visual UA  which has no
visual representation, [...]
This use case may be far-fetched, but it can be useful to link to a point
within a document in order to add future representations, rather than merely
reference existing bits of previously existing representation. Being able to
reference arbitrary points of a document - with or without existing bits of
representation - is a more general capability.