I will implement it in a future release.
Take a look in the designer help:
ACTIONCD (16) means saved action CD records; non-Computable; canonical form.
ASSISTANTINFO (17) means saved assistant information; non-Computable; canonical form.
ATTACHMENT (1084) means file attachment.
AUTHORS (1076) means authors.
Note This value is new with Release 6.
DATETIMES (1024) means date-time value or range of date-time values.
EMBEDDEDOBJECT (1090) means embedded object.
ERRORITEM (256) means an error occurred while accessing the type.
FORMULA (1536) means Notes formula.
HTML (21) means HTML source text.
ICON (6) means icon.
LSOBJECT (20) means saved LotusScript Object code for an agent.
MIME_PART (25) means MIME support.
NAMES (1074) means names.
NOTELINKS (7) means link to a database, view, or document.
NOTEREFS (4) means reference to the parent document.
NUMBERS (768) means number or number list.
OTHEROBJECT (1085) means other object.
QUERYCD (15) means saved query CD records; non-Computable; canonical form.
READERS (1075) means readers.
RICHTEXT (1) means rich text.
SIGNATURE (8) means signature.
TEXT (1280) means text or text list.
UNAVAILABLE (512) means the item type isn't available.
UNKNOWN (0) means the item type isn't known.
USERDATA (14) means user data.
USERID (1792) means user ID name.
VIEWMAPDATA (18) means saved ViewMap dataset; non-Computable; canonical form.
VIEWMAPLAYOUT (19) means saved ViewMap layout; non-Computable; canonical form.