Document use of ~/.<program>rc.

@@ -30,30 +30,38 @@ inconvenient to specify them in the command line each time you run
 a mailutils utility. The @dfn{configuration files} provide a way to
 add default command line arguments without having to type them in
 the command line. Upon startup, each mailutils utility scans and
-processes the contents of the two startup files: the site-wide
-configuration file @file{mailutils.rc} and user-specific configuration
-file @file{.mailutils}. The site-wide configuration file is searched
+processes the contents of the three startup files: the site-wide
+configuration file @file{mailutils.rc}, the user-specific configuration
+file @file{.mailutils}, and the program-specific configuration
+file @file{.<program>rc}. The site-wide configuration file is searched
 in your system configuration directory (usually, @file{/etc} or
-@file{/usr/local/etc}), the user-specific configuration file is searched
-in user home directory.
+@file{/usr/local/etc}), the user-specific and program-specific
+configuration files are searched in the user's home directory.
 
-Both files have simple line-oriented syntax. Comments begin with the
+These files have simple line-oriented syntax. Comments begin with the
 pound sign (@samp{#}) and extend through the end of the line
 @footnote{If @samp{#} is not the first character on the line, it
 should be separated from the previous word by any amount of whitespace.}.
 Very long lines may be split across several lines by escaping final newline
 with a backslash (@samp{\}) character.
 
-Any non-comment line starts with a @dfn{tag}. A tag is either a name
-of a particular mailutils utility or @dfn{option group}, prefixed with
-colon (@samp{:}). The command line options common for several mailutils
-programs are divided into @dfn{option groups} or @dfn{capabilities},
-e.g. the options @option{--maildir} and @option{--license} form group
-@samp{mailutils}. These groups are discussed in detail below.
-
-When processing the configuration file, a mailutils utility selects
-those lines, whose tag is either the name of that utility or the name
-of the option group supported by it. For each line found, its tag
+In the non-program-specific configuration files, any non-comment line
+must start with a @dfn{tag}. In the program-specific configuration
+file the tag must not be present, all options are for the specific
+program.
+
+A tag is either a name of a particular mailutils utility or @dfn{option
+group}, prefixed with colon (@samp{:}). The command line options common for
+several mailutils programs are divided into @dfn{option groups} or
+@dfn{capabilities}, e.g. the options @option{--maildir} and
+@option{--license} form group @samp{mailutils}. These groups are discussed
+in detail below.
+
+When processing the non-program-specific configuration files
+(@file{mailutils.rc} and @file{.mailutils}), a mailutils utility selects
+those lines whose tag is either the name of that utility or the name
+of the option group supported by it. In the program-specific configuration
+file, all lines are selected. For each line found, its tag (if present)
 is stripped away, and the rest of the line is split up into words.
 These words are regarded as command line options and are inserted to
 the program arguments @emph{before} any options from the command line.