XHTML requires them, while HTML leaves them optional. Perlmonks seems to use transitional, in HTML mode. Which means it should be ok, in theory.
That said, the interactions between them and a several of the other HTML tags that are allowed here can get fairly complex, and it is not always obvious — even with the spec — which way they are supposed to be resolved.
Consider them something that use warnings; will complain about. ;)
In reply to Re^4: Wiki-Style syntax for posting
by DStaal
in thread Wiki-Style syntax for posting
by Anonymous Monk
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