the terms for to and from

I've been looking at the terms "to" and "from" wrt a transfer in webcredits
/ opentransact / payswarm and pingback ongologies

Payswarm uses

source
destination

Opentransact uses

to
from

Pingback uses

source
target

There's a slight complexity in that pingback has a "to" field to which is
your pingback service.  So there's possible collisions of named query
variables a theoretical possibility.

Of these 3 I think that "to" and "from" are the most intuitive, due to
similarity to email / sms etc.

I'm considering changing web credits to use these fields.

Any thoughts?