-section (and, if necessary, its parent in turn, and so on). Note that
+sections (and, if necessary, their parents in turn, and so on).
+.PP
+.hP \*o
+If a value can be found for a key via multiple parents then all of them
+must report the
+.I same
+value. This restriction may be relaxed somewhat, if it turns out that a
+more flexible notion of multiple inheritance is useful.
+.hP \*o
+It's not allowed for a section to inherit, possibly indirectly, from
+itself. Currently errors of this kind are only diagnosed when a cycle
+is encountered while looking up a key and none of the sections on the
+path from the original section up to and round the cycle define a value
+for it. Future versions of this program might be more picky.
+.PP
+Note that