Something that separates blocks of HTML, such as <hr>
(I know I put one of those around here somewhere...
Ah! ^ There it is!!! ;-)
Yet another one... Four or more '-' chars at the start of a line equals <hr> in Wiki.
One more, just for the sake of it-
A hierarchy of HorizontalSeparators using dashes, underscores and indented dashes:
_______________ --------------- --------------- _______________