I see a need to start establishing "standard" paths for configuring rpm
or I'm going to go insane.

rpm itself has these __DIRECTORY__ paths used for configuration:

     %_usrlibrpm           /usr/lib/ 
rpm                                          default rpm configuration
                                      %{_usrlibrpm}/% 
{_target}                 CPU-OS 2-tuple configuration
     %_etcrrpm              /etc/ 
rpm                                                per-system  
configuration
                                       
~/                                                            per- 
user configuration

In order to support per-vendor configuration, these 2 additional  
directories were added:
                                      %{_usrlibrpm}/% 
{vendor}                  per-vendor configuration
                                      %{_usrlibrpm}/% 
{_target_platform} CPU-VENDOR-OS 3/4 tuple configuration

In order to achieve rpm version interoperability, rpmhome was used  
with either
      %_rpmhome         %{_usrlibrpm}/%{_rpmversion}        per- 
version configuration
or
      %_rpmhome         %{_usrlibrpm}-%{_rpmversion}        per- 
version configuration
variants.

Now rpm-4.5.90 has decided on
                                        %{_usrlibrpm}/platform/% 
{_target_platform}

Then there is the issue of multilib, basically an alternative choice  
on ELF64
     %_usrlibrpm           /usr/lib64/ 
rpm                                        default rpm configuration

There's likely a proliferation of target subdirs into vendor/system  
configuration
directories.

I can easily chase macros/rpmpopt into various alternative trees if  
all subdirs of
%{__usrlibrpm} and %{__etcrpm} are traversed with a filter to select  
directory
(e.g. %{_rpmversion} or %{_target} or %{vendor} or % 
{_target_platform} or ...)
looking for macros* and/or rpmpopt* to read within that directory.

Personally, I specifically dislike
      %_rpmhome         %{_usrlibrpm}-%{_rpmversion}        per- 
version configuration
and
     %_usrlibrpm           /usr/lib64/ 
rpm                                        default rpm configuration
but I can live with either of the above __IF__ rules for how rpm  
configuration is read
can be established.

Are there any other configuration __DIRECTORIES__ that need to be  
added to the mess above?

73 de Jeff