-The m17n library expects that the function mdatabase_load () returns a
-plist of a specific format on loading data identified by a specific
-set of tags. As the plist format used for the database data is
-strongly limited, we can use the equivalent text of simple syntax
-(S-expression) to represent the plist as below.
-
-The text consists of one or more @e elements . Each element
-represents a property, i.e. a single element of a plist, and the
-sequence of the elements constitute a plist.
-
-Elements are separated by one or more @e whitespaces, i.e. a space
+The mdatabase_load () function returns the data specified by tags in
+the form of plist if the first tag is not @c Mchartable nor @c
+Mcharset. The keys of the returned plist are limited to
+<tt>Minteger</tt>, <tt>Msymbol</tt>, <tt>Mtext</tt>, and
+<tt>Mplist</tt>. The type of the value is unambiguously determined by
+the corresponding key. If the key is <tt>Minteger</tt>, the value is
+an integer. If the key is <tt>Msymbol</tt>, the value is a symbol.
+And so on.
+
+A number of expressions are possible to represent a plist. For
+instance, we can use the form <tt>(K1:V1, K2:V2, ..., Kn:Vn)</tt> to
+represent a plist whose first property key and value are K1 and V1,
+second key and value are K2 and V2, and so on. However, we can use a
+simpler expression here because the types of plists used in the m17n
+database are fairly restricted.
+
+Hereafter, we use an expression, which is similar to S-expression, to
+represent a plist. (Actually, the default database loader of the m17n
+library is designed to read data files written in this expression.)
+
+The expression consists of one or more <i>elements</i>. Each element
+represents a property, i.e. a single element of a plist.
+
+Elements are separated by one or more <i>whitespaces</i>, i.e. a space