Tag 109 - client ID

Imported from previous forum

[ original email was from Steve Glickstein - sglickstein@warburg.com ]
I’m finding tag 109 a bit confusing. The spec says “Used for firm identification in third-party transactions”. Does the absence of data imply the order is NOT a third party transaction? Does the existance of data imply a third party transaction?

Should the broker reject the order, if a third-party is NOT used and tag 109 has data?

I suggest the spec read "tag 109 is required to be blank, unless the order is sent via a third-party."