+.SH CONFIGURATION FILE
+.P
+Any of the command-line options mentioned above can be specified in a
+configuration file instead. We first look for \(dqhtsnrc\(dq in the
+system configuration directory. We then look for a file named
+\(dq.htsnrc\(dq in the user's home directory. The latter will override
+the former.
+.P
+The user's home directory is simply $HOME on Unix; on Windows it's
+wherever %APPDATA% points. The system configuration directory is
+determined by Cabal; the \(dqsysconfdir\(dq parameter during the
+\(dqconfigure\(dq step is used.
+.P
+The file's syntax is given by examples in the htsnrc.example file
+(included with \fBhtsn\fR).
+.P
+Options specified on the command-line override those in either
+configuration file.
+