Re: Locating RFC [2]822 headers

> The existence of a header in such a registry need not mean
> that this header is "legal" other than when the registry
> refers to a standard for the definition of the header.
> The existence could just be interpreted that you should
> not re-use an existing header name for a new purpose.
yes, but this really does cause a problem, as the set of
"obvious" field names for some purpose is rather small, and
there is a tendency for the "obvious" field names to get
usurped by naive implementations.