A letter being registered consignment (accepted by acknowledgment of acceptance and delivered by acknowledgment of receipt), or postal parcel, which is received, sorted, carried and delivered in a way that ensures together:
a) direct receipt of a postal consignment from the sender,
b) tracking postal consignment from sending to delivery,
c) delivery of postal consignment within a guaranteed period specified in the regulations of postal services or contracts for postal services,
d) delivery of postal consignment directly into the hands of the addressee or the person entitled to receive,
e) obtaining acknowledgment of receipt of postal consignment in written or electronic form.

Until 2013 (added-value)express mail was called.