Methods can also have the property of "idempotence" in that (aside from error or expiration issues) the side-effects of N > 0 identical requests is the same as for a single request. The methods
DELETEshare this property. Also, the methods
TRACESHOULD NOT have side effects, and so are inherently idempotent.
That is, idempotence is about the effect of the request, not about the response code that you get.