Many packages of software have READMEs and other documentation as part of the source package. Red Hat Linux uses a standard place to install those documents so that you don't have to install the sources to look at the documents. All of those documents are stored in subdirectories of /usr/doc. The subdirectory depends on the package. Each package that has extra documentation will create a directory called packagename-version-releasenumber. For example, the tin package might be version 1.22 and release number 2. The path to its documentation would be /usr/doc/tin-1.22-2.
For the most part, the documents in this directory are ASCII. You can usually view them with more filename or less filename. This is nice, but what if you want to see if there is documentation for a specific command or file and you don't know the package it came from? It doesn't matter! You can simply enter:
rpm -qdf /etc/sendmail.cf
This will report all the documentation from the package containing the file /etc/sendmail.cf. Commands like this are covered more in depth in the RPM-HOWTO , available from www.redhat.com.
Also, what if it's a command you need help with and the man page isn't good? You could do something like:
rpm -qdf `which COMMAND`
Again, ``COMMAND'' is the actual command you need help with. This will work only when the command is on your path.