%buildroot vs. $RPM_BUILD_ROOT again (was: New package : ncftp)

[Michael Schwendt]

On Sun, 06 Mar 2005 09:28:43 -0600, Tom 'spot' Callaway wrote:

> On Sun, 2005-03-06 at 16:02 +0100, Nicolas Mailhot wrote:
> 
> >Well, I'm pretty sure I'm only relaying his clarification on this list
> >(won't hunt it in the archives though). As long as you don't mix stuff,
> >it's ok to use whatever you prefer.
> 
> http://www.fedora.us/pipermail/fedora-devel/2003-April/001155.html
> 
> Wherein, Jeff says "$RPM_BUILD_ROOT is the official, supported,
> mechanism for getting the value of the configured build root in a build
> scriptlet."
> 
> Thus, the Fedora Extras Packaging Guidelines state that you should not
> use %{buildroot} (refer to:
> http://fedoraproject.org/wiki/PackagingGuidelines#BadMacros).

To request clarification, as these are guidelines and not policies:

: Macros that you should NOT use
:
: Do not use the %{buildroot} macro, use the $RPM_BUILD_ROOT variable instead.
: Do not use the %{optflags} macro, use the $RPM_OPT_FLAGS variable instead.

In the English language I'm used to, "do not" means "you must not" and
differs from "you should not".

So, what is it here? "Must not" or "should not"? Policy or guideline?