+ In implementing complex hierarchical widgets (_e.g._, using the
+`group' widget), the following functions may be useful. The syntax for
+the TYPE arguments to these functions is described in *Note Basic
+Types::.
+
+ - Function: widget-create-child-and-convert parent type &rest args
+ As a child of PARENT, create a widget with type TYPE and value
+ VALUE. TYPE is copied, and the `:widget-contvert' method is
+ applied to the optional keyword arguments from ARGS.
+
+ - Function: widget-create-child parent type
+ As a child of PARENT, create a widget with type TYPE. TYPE is
+ copied, but no conversion method is applied.
+
+ - Function: widget-create-child-value parent type value
+ As a child of PARENT, create a widget with type TYPE and value
+ VALUE. TYPE is copied, but no conversion method is applied.
+
+ - Function: widget-convert type &rest args
+ Convert TYPE to a widget without inserting it in the buffer. The
+ optional ARGS are additional keyword arguments.
+
+ The widget's `:args' property is set from the longest tail of ARGS
+ whose `cdr' is not a keyword, or if that is null, from the longest
+ tail of TYPE's `:args' property whose cdr is not a keyword.
+ Keyword arguments from ARGS are set, and the `:value' property (if
+ any) is converted from external to internal format.
+
+ `widget-convert' is typically not called from user code; rather it
+is called implicitly through the `widget-create*' functions.
+