It's possible to dump the available / defined macros when authoring a RPM spec file by using:
rpm --showrc or rpm --eval %dump
or including the %dump builtin macro in the spec file itself and examining the output from the RPM build process (the build output contains macro definitions).
In either case, some of the lines are prefixed with "-14" or "-11". The lines without either appear to be the body of multi-line definitions.
What is the significance of the "-14" (or less common "-11") in this output? More importantly I'm interested in knowing where this is documented.
Sample Output:
-14: __autoconf autoconf
-14: __autoheader autoheader
-14: __automake automake
-11= _target_cpu x86_64
-11= _target_os linux
References: