samo prijedlog.. na google-u se dosta nalazi ovaj izraz, a mozete evetualno upotrijebiti rijec consignment umjesto shipment (ili cak cargo, ali mozda vam nece odgovarati kontekstu).

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Note added at 29 mins (2008-06-23 17:18:07 GMT)
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ili valuable cargo, mislim da je to najbolje, tzv. val-posiljka:
www.flylalcargo.com/en/extra/useful_info/expensive_shipment
hr.wikipedia.org/wiki/Zračna_luka

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Note added at 29 mins (2008-06-23 17:18:59 GMT)
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ili expensive shipment, kako vam se vidi iz prvog linka...

A written order for the payment of a sum to a named individual; obtainable and payable at a post office.

e sad, ako se govori o vrijednosnim pismima opcenito, a ne samo o gotovini, znaci moze biti i cek ili bilo kakva stvar za koju mi odredimo da ima vrijednost (obicno kada saljete preporuceno pismo vas na posti pitaju da li ima kakvu vrijednost, jer se onda dodatno osigura).
to se obicno zove "insured letter", iako svaka posta ima svoja imena - npr. u UK je to Royal Mail Special delivery
http://www.royalmail.com/portal/campaign/content1?catId=1000...

evo neki primjeri:
Irska - insurance service
http://www.anpost.ie/AnPost/PostalRates/PostalRatesHome.htm?...

Juzna Afrika
This document is an abbreviated version of the insurance policy for the loss or damage of insured letters/parcels
http://www.sapo.co.za/Documents/FAIS-Nova abridged Insurance...


Mail containing money, securities, precious metals, products made from precious metals, and other valuables should be sent as Insured Items.
http://www.posti.fi/english/cardsandletters/additionalservic...


http://www.posta.si/DesktopModules/ViewDocument.aspx?Documen...
http://www.posta.si/Namizje.aspx?tabid=584


a ako se radi samo o slanju novca, onda je to money transfer kao npr. https://www.westernunion.it/WUCOMWEB/staticMid.do?method=loa...