first, last, previous, next
first==self, nextprevious must be omittedlast==self, previousnext must be omittedfh:complete is also presentprev-archive, next-archive
fh:complete is also presentcurrent does not existfh:archive is not also presentcurrent
fh:archive is not also presentfh:complete is present, and current link doesn't match selffh:archive
current link is not presentprev-archive, next-archive, or fh:complete does not existfh:complete
current link is not present ?