@startuml
skinparam dpi 400
' Remove shadows
skinparam shadowing false

actor Donor 
actor Charity
participant Donau
actor TaxAuthority

loop during the year
Donor -> Charity: issue receipt, pay donation
activate Charity
Charity -> Donau: issue receipt
activate Donau
Donau --> Charity: receipt
deactivate Donau
Charity --> Donor: receipt
deactivate Charity
end loop
Donor -> Donau: summarize receipts from the year
activate Donau
Donau --> Donor: overall donation statement
deactivate Donau
Donor --> TaxAuthority: submit manually the tax return with the donation statement
@enduml
