+* `VOID autosearch()` --
+ Registers that this kind of widget is one that requires an
+ automatic search to be run for it if an `autosearch` attribute
+ is provided on the HTML element. This is appropriate for
+ widgets such as `Records` and `Facet` that display some part
+ of a search result.
+
+* `VOID hideWhenNarrow()` --
+ Registers that this widget should hide itself when the page
+ becomes "narrow" -- that is, fewer pixels in width that the
+ threshhold value specified by the top-level configuration item
+ `responsive_design_width`. Should be used for "unimportant"
+ widgets that can be omitted from the mobile version of a site.
+
+* `expandValue()` --
+ TODO: either document this or remove it from the API.
+
+* TODO subwidget()
+
+In addition to these properties and methods of the bare widget object,
+some kinds of specific widget add other properties of their own. For
+example, the `Builder` widget uses a `callback` property as the
+function that it use to publish the widget definition that it
+constructs. This defaults to the builtin function `alert`, but can be
+overridden by derived widgets such as `ConsoleBuilder`.
+