+
+<subsection>
+<heading>parameter_class</heading>
+<para>
+Each parameter is defined to be of a certain <emph>class</emph>.
+The class defines which properties a parameter of that class may have.
+</para>
+
+<subsubsection>
+<heading>The fields</heading>
+<para>
+The fields of the <emph>parameter_class</emph> table are listed below:
+</para>
+<table cpos='lllp{6cm}'>
+ <thead>
+ <col> Fieldname </col> <col> Fieldtype </col> <col> Size </col>
+ <col> Remarks </col>
+ </thead>
+ <row>
+ <col>name</col><col>text</col><col> </col>
+ <col>Name of the class</col>
+ </row>
+ <row>
+ <col>property_name</col><col>text</col><col> </col>
+ <col>Name of the property. Used in property table.</col>
+ </row>
+ <row>
+ <col>description</col><col>text</col><col> </col>
+ <col>A verbose description of the property</col>
+ </row>
+ <row>
+ <col>property_type</col><col>text</col><col> </col>
+ <col>Either 'STATIC' or 'DYNAMIC'</col>
+ </row>
+ <row>
+ <col>min</col><col>float</col><col>4</col>
+ <col>The default minimum value of the property.</col>
+ </row>
+ <row>
+ <col>max</col><col>float</col><col>4</col>
+ <col>The default maximum value of the property.</col>
+ </row>
+ <row>
+ <col>notify</col><col>boolean</col><col>1</col>
+ <col>If TRUE, create a notification when something about the property or
+ the parameter changes.
+ </col>
+ </row>
+
+</table>
+
+<para>
+The combination of name and property_name must be unique.
+Note that the <emph>min</emph> and <emph>max</emph> fields are used
+only for properties of a numerical nature.
+</para>
+
+</subsubsection>
+<subsubsection>
+<heading>Sample data</heading>
+
+<para>
+The table below lists a few examples of parameter classes
+</para>
+<table cpos='lllllll'>
+ <thead>
+ <col>name</col><col>property_name</col><col>description</col><col>property_type</col>
+ <col>min</col><col>max</col><col>notify</col>
+ </thead>
+ <row>
+ <col>package</col><col>version</col><col>The installed version</col><col>STATIC</col>
+ <col> </col><col> </col><col>true</col>
+ </row>
+</table>
+</subsubsection>
+</subsection>
+
+
+<subsection>
+<heading>parameter_notification</heading>
+<para>
+The parameter_notification table defines the relationship between <emph>parameters</emph>
+and <emph>notifications</emph>.
+Whenever a parameter is changed, i.e. the parameter is created, one of its
+properties changed or a parameter is removed, this may result in a notification.
+This table provides the link between that notification and the change in
+parameter that the notification is about.
+Note that a single notification may be created for a number of changes in
+parameters.
+</para>
+
+<subsubsection>
+<heading>The fields</heading>
+<para>
+The fields of the <emph>parameter_notification</emph> table are listed below:
+</para>
+<table cpos='lllp{6cm}'>
+ <thead>
+ <col> Fieldname </col> <col> Fieldtype </col> <col> Size </col>
+ <col> Remarks </col>
+ </thead>
+ <row>
+ <col>notificationid</col><col>bigint</col><col>8</col>
+ <col>The notification for the changed parameters. Refers to the notification table.</col>
+ </row>
+ <row>
+ <col>paramid</col><col>bigserial</col><col>8</col>
+ <col>The parameter for which the notification is made. Refers to the parameter table.</col>
+ </row>
+</table>
+
+<para>
+The combination of notificationid and paramid must be unique.
+</para>
+
+</subsubsection>
+</subsection>
+