Caller tokens

[Aaron Soules]

Hello,

Got a newb question. When I'm installing payment instructions, is the
returned caller token something i need to generate for each
transaction, or something i should save in my DB and keep using on
every transaction? The blog post here (http://edgenic.com/2009/01/24/
software-as-a-service-with-amazon-fps-using-remit-for-ruby/) says that
caller and recipient tokens are generated once, but it doesn't specify
whether thats once forever, or once per transaction.

Thanks!

-Aaron