Understanding "Standard Tag Lists" vs "Forward Tag Lists"

Retreaver released a "Forward tags list" feature, this new list allows for tags to be added to buyers, which alters the time when the tag list is evaluated.

Standard Tag Lists

Standard tag lists are evaluated BEFORE the buyer is selected - for 95% of use cases, this is where you will want to place most of your buyer tags. IE "Age must be Over 65", Bid/Revenue must be over $10, Zip Code/Geographic based conditions, Etc.

Forward Tag Lists

Forward tag lists are evaluated AFTER the buyer is selected, but just prior to the call being routed. The purpose of this functionality is to support deferring validation based webhook logic such as verifying a lead, ensuring they are not on any federal do-not-call or blacklists but WITHOUT necessarily having to trigger those costly webhooks for every incoming Real-Time-Bidding request. In other words, The forward tag list essentially defers/delays any present 'forward tags' for evaluation until the moment before the buyer is routed. 

Proper usage of Forward Tag Lists with Validation Webhooks

Instead of triggering blacklist/validation webhooks as 'passthrough/call start' triggered webhooks, you now would move those to 'when the buyer is selected', and enable the 'hold call' check box so the Blacklist/validation webhook only triggers once a call enters the system and is just about to route to the buyer, saving you from unnecessarily triggering blacklist/validation API requests for the larger portion of RTB calls that either route to another buyer or don't arrive at all.

Retreaver Webhook Rate Limiting Note

Note: If you hit a temporary webhook rate limitation, your buyer would not trigger any subsequent webhooks. If one of those webhooks was meant to return a tag ( say a blacklist validation check ), but it does not trigger - the buyer would effectively remain un-routable at that moment since we could not determine the blacklist/validation response status. That behavior has existed for some time, and remains uncharged with the introduction of the forward tags system.