IMAPSieve Changed flags cause?

[MRob]

On 2017-04-08 01:03, Stephan Bosch wrote:
> Op 4/7/2017 om 7:29 PM schreef MRob:
>> On 2017-04-05 18:50, MRob wrote:
>>> RFC 6785 says I should be able to run scripts when a command changes
>>> flags on a message but I can't understand what to put in
>>> imapsieve_mailboxXXX_causes. Dovecot logs something like STORE as an
>>> invalid cause.
>>> 
>>> How do I run an administrator Sieve script caused from change in 
>>> flags?
>> 
>> Is no reply on this to mean the feature is not currently supported, or
>> everyone's busy?
>> 
>> If not supported, are there plans to support admin scripts being
>> triggered from message flag changes?
> 
> It is in the specification:
> 
> https://tools.ietf.org/html/rfc6785#section-4.3

Yes, that's what I referenced when I asked my question. But I cannot 
determine how to configure Dovecot to trigger an admin script based on 
such an event. If you can, please clarify (the docs don't mention this 
case).