Описание тега rpm-spec
The rpm spec file contains the information required by RPM to build a package.
The spec file is at the heart of RPM's packaging building process. Similar in concept to a makefile, it contains information required by RPM to build the package, as well as instructions telling RPM how to build it. The spec file also dictates exactly what files are a part of the package, and where they should be installed.
(From the max-rpm book)
This tag is closely related to rpm and rpmbuild. You should research those tags to see if a similar question exists.