To describe the DBMS_PIPE package in any detail here would take far too long - I intended the post to be a pointer as to what you needed to look up in the manuals.

The package contains the following functions and procedures:

create_pipe
next_item_type
pack_message
receive_message
remove_pipe
reset_buffer
send_message
unique_session_name
and
unpack_message

Any of the PL/SQL programming guides should be able to give you the information that you need.

HTH

David.