Sample tag trade process

Paritipants: 2 users (A, B) + 1 developer (D)
Messages sent (e.g. to a mailing list):
A: Specification [task] [paym]
B: Financial support intention [paym]
D: Start declaration [strt]
D: Solution [done]
(A pays D using Paypal)
(B pays D using bank transfer)
A: Rating for D [rate]
B: Rating for D [rate]
D: Rating A and B [rate] [rate]