When verifying a package, RPM produces output only if there is a verification failure. When a file fails verification, the format of the output is a bit cryptic, but it packs all the information you need into one line per file. Here is the format:
SM5DLUGT c file
It's unlikely that every file attribute will fail to verify, so each of the eight attribute flags will only appear if there is a problem. Otherwise, a ``.'' will be printed in that flag's place. Let's look at an example or two:
In this case, the mode, MD5 checksum, and modification time for the specified file have failed to verify. The file is not a config file (Note the absence of a ``c'' between the attribute list and the filename).
S.5....T c /etc/passwd
Here, the size, checksum, and modification time of the system password file have all changed. The ``c'' indicates that this is a config file.
This last example illustrates what RPM does when a file, that should be there, is missing entirely.
When rpm -V finds other problems, the output is a bit easier to understand:
# rpm -V blather
Unsatisfied dependencies for blather-7.9-1: bother >= 3.1
It's pretty easy to see that the blather package requires at least version 3.1 of the bother package.
The output from a package's verification script is a bit harder to categorize, as the script's contents, as well as its messages, are entirely up to the package builder.