Excessive Multi-Posting or Multiple Posts: The same post made multiple times to the same group(s). Sometimes called "Billboarding" or "Hammering" Most service-providers have limits on that as well as ECP, so there too you would need to read your service-provider's policies to determine the maximum allowed. Note that in the Warez groups ONE identical post (per day) is the maximum the group's users consider appropriate (barring the occasional slip of the ENTER-key, of course.). Any more than that is considered "Billboarding" or "Hammering", and the author is often kill-filed on sight.
Excessive Multi-Posting. Posting an article to dozens of newsgroups or more, one newsgroup per post. Worse than ECP, because it consumes much more bandwidth and is a greater annoyance to readers. The FAQ states that EMP means, essentially, "too many separate copies of a substantively identical article".