Specify how to handle modifier lists.

Give example.

Rename to be slightly better.

Quoting!

Type Modelica keywords in bold and remove trailing whitespaces ;-)

Modelica/package.mo

@@ -1314,8 +1314,35 @@ The keywords <code>public</code> and <code>protected</code> are headings for a&n
 of declarations.
 </p>
 <p>
+Long modifier lists shall be split into several indented lines with at most one modifier per line.
+</p>
+<p>
 Full class definitions shall be separated by an empty line.
 </p>
+
+<h5>Example</h5>
+
+<blockquote><pre>
+<strong>package</strong> MyPackage
+  <strong>partial</strong> <strong>model</strong> BaseModel
+    <strong>parameter</strong> Real p;
+    <strong>input</strong> Real u(unit=\"m/s\");
+  <strong>protected</strong>
+    Real y;
+    Real x(
+      start=1,
+      unit=\"m\",
+      nominal=10);
+  <strong>equation</strong>
+    <strong>der</strong>(x) = u;
+    y = 2*x;
+  <strong>end</strong> BaseModel;
+
+  <strong>model</strong> ModelP2
+    <strong>extends</strong> BaseModel(p=2);
+  <strong>end</strong> ModelP2;
+<strong>end</strong> MyPackage;
+</pre></blockquote>
 </html>"));
        end Format;