FND_WEBATTCH.ADD_ATTACHMENT for suppliers - w9 - R12.2

What's the proper method to add attachments to suppliers in R12.2 using FND_WEBATTCH?

Is there documentation on FND_WEBATTCH yet?

Ultimately I'd be using this to add attachments to Invoices, POs, Projects, Suppliers, Journal Entries. with either URLs or the file itself.

Which function name/entity_name do I use for the above modules?

Invoices:

function_name = APXINWKB

entity_name = AP_INVOICES

POs:

Function_name =

entity_name =

Projects:

Function_name =

entity_name =

Suppliers

Function_name =

Entity_name =

Journal Entries:

Function_name =

Entity_name =

  fnd_webattch.add_attachment(

            seq_num                 => 100

           ,category_id             => v_category_id

           ,document_description    => v_description

           ,datatype_id             => 5 --url