Consent mode v2 introduced with ad_user_data and ad_personalization parameters

Google updated consent mode in November 2023 to add two parameters, ad_user_data and ad_personalization, alongside ad_storage and analytics_storage, and said advertisers using audiences or personalized ads for EEA users would need to send them from March 2024 under the EU user consent policy and the Digital Markets Act.

Google's developer guide states consent mode 'was updated in November, 2023'. Google Tag Manager templates and CMP integrations were updated to send the new signals; the gcd URL parameter encodes all four states.