You can set various parameters for the refdb clients on the command line each time you start them, but this is tedious and error-prone. We're all lazy by nature, so refdb allows you to set defaults in configuration files. You can still override these defaults by using command-line options on a per-session base, but usually you won't have to.
You'll have to deal with two refdb clients: refdbc is the reference management client, and refdbib is the bibliography client (you won't run this client directly and rather use a script, but you'll have to configure the client anyway). The configuration files are aptly named .refdbcrc and .refdbibrc for refdbc and refdbib, respectively, and they should reside in your home directory. These are plain-text files with a simple syntax that you can create and edit with your favourite text editor.
The following code example shows the configuration file .refdbcrc, using the values that we assumed above.
# This is the user configuration file for refdbc serverip 127.0.0.1 username markus passwd secret defaultdb refs pager less toencoding ISO-8859-1 fromencoding ISO-8859-1
The line starting with the hash sign (#) is a comment. You can add more comment lines if you want to, or leave out the comment line in the example if you remember what that file is good for anyway.
If you (or your administrator) don't feel comfortable with storing your password in a plain-text file, you can use an asterisk "*" instead. This will cause the refdb clients to ask for the password interactively at startup.
Now what does the configuration file .refdbibrc look like? It is the same with the exception of the last line. You can simply create a copy and name it .refdbibrc, remove the last line, and you're done.