Do you use 
LocationGroups in 
CampaignCriterion? If so, read on to learn about a new key in the 
Forward Compatibility Map to identify whether a Location Group is compatible with the AdWords user interface or the API.
Through the Campaign Settings tab of the user interface and the AdWords API 
CampaignCriterionService, you can create a 
LocationGroups campaign criteria to target locations within a specific radius around all of your campaign's location extensions.

The user interface also allows you to further restrict the 
LocationGroups criterion to location extensions within 
geographical targets or 
Cities-DMA regions. However, the AdWords API does 
not currently support modifying these additional settings.
To indicate in the AdWords API that someone created a configuration of the latter form through the user interface, the 
CampaignCriterion.forwardCompatibilityMap has a new key called 
LocationGroups.locationId.
  | Key | Read-Only | Value Description | IMPORTANT | 
| 
ServiceCampaignCriterionService
 Entity
 CampaignCriterion
 Key Name
 LocationGroups.locationId
 | 
Yes |  |  | 
We’re working to support the 
geographical targets and 
Cities-DMA regions option in future API versions.
Be on the lookout for an upcoming addition to the 
Forward Compatibility Map regarding which feed ID will be used for proximity targeting. 
Questions? Visit us on the 
AdWords API Forum or our 
Google+ page.
 Nadine Sundquist, AdWords API Team
 Nadine Sundquist, AdWords API Team