+=item C<part_picker $name, $value, %params>
+
+All-in-one picker widget for parts. The name will be both id and name
+of the resulting hidden C<id> input field (but the ID can be
+overwritten with C<$params{id}>).
+
+An additional dummy input will be generated which is used to find
+parts. For a detailed description of it's behaviour, see section
+C<PART PICKER SPECIFICATION>.
+
+C<$value> can be a parts id or a C<Rose::DB:Object> instance.
+
+If C<%params> contains C<type> only parts of this type will be used
+for autocompletion. You may comma separate multiple types as in
+C<part,assembly>.
+
+If C<%params> contains C<unit> only parts with this unit will be used
+for autocompletion. You may comma separate multiple units as in
+C<h,min>.
+
+If C<%params> contains C<convertible_unit> only parts with a unit
+that's convertible to unit will be used for autocompletion.
+
+Obsolete parts will by default not displayed for selection. However they are
+accepted as default values and can persist during updates. As with other
+selectors though, they are not selectable once overridden.
+
+Currently you must include C<js/autocomplete_part.js> in your controller, the
+presenter can not do this from the template.
+
+=back
+
+=head1 PART PICKER SPECIFICATION
+
+The following list of design goals were applied:
+
+=over 4
+
+=item *
+
+Parts should not be perceived by the user as distinct inputs of partnumber and
+description but as a single object
+
+=item *
+
+Easy to use without documentation for novice users
+
+=item *
+
+Fast to use with keyboard for experienced users
+
+=item *
+
+Possible to use without any keyboard interaction for mouse (or touchscreen)
+users
+
+=item *
+
+Must not leave the current page in event of ambiguity (cf. current select_item
+mechanism)
+
+=item *
+
+Should be useable with hand scanners or similar alternative keyboard devices
+
+=item *
+
+Should not require a feedback/check loop in the common case
+
+=item *
+
+Should not be constraint to exact matches
+
+=back
+
+The implementation consists of the following parts which will be referenced later:
+
+=over 4
+
+=item 1
+
+A hidden input (id input), used to hold the id of the selected part. The only
+input that gets submitted
+
+=item 2
+
+An input (dummy input) containing a description of the currently selected part,
+also used by the user to search for parts
+
+=item 3
+
+A jquery.autocomplete mechanism attached to the dummy field
+
+=item 4
+
+A popup layer for both feedback and input of additional data in case of
+ambiguity.