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title: "Limit Ad Tracking (LMT) Processing Logic"
canonical: "https://hub.freewheel.tv/space/BC/113999953/Limit%20Ad%20Tracking%20(LMT)%20Processing%20Logic"
format: markdown
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Overview LMT (Limit Ad Tracking) is a device-level privacy signal sent by mobile apps when a user opts out of personalized advertising. When   lmt=1   is present in a bid request, it means: The user has requested not to be tracked. Personal identifiers (PII) such as device IDs and geolocation should not be used. This signal is commonly seen in: COPPA (children's) inventory Privacy-focused apps and OS settings Android environments where users opt out of ad personalization Buyer Cloud's logic for handling  LMT=1  bid requests applies automatically to all traffic. It is  aligned with IAB’s interpretation of LMT and is COPPA/CCPA-compliant. How Buyer Cloud Processes LMT=1 Bid Requests All bid requests with  lmt=1  are accepted, across all devices and operating systems. To comply with privacy regulations, FreeWheel enforces the following behaviors: Personal Data Obfuscation Behavior The following commonly used RTB fields are considered "Personal Data". To protect this data, bid requests flagged with LMT=1 will have changes made  to the following fields when passed in macros, bidding agent requests, augmentor requests, and log files: Raw Log Field Name Proto Field Name Data Handling platform_device_ifa Device.ifa Blank platform_device_idfa Device.idfa Blank platform_device_didmd5 Device.didmd5 Blank platform_device_didsha1 Device.didsha1 Blank platform_device_dpidmd5 Device.dpidmd5 Blank platform_device_dpidsha1 Device.dpidsha1 Blank user_id N/A Blank geo_lat Device.lat Truncated to 3 decimal place s geo_long Device.long Truncated to 3 decimal plac es ua Device.ua Blank ip_address Device.ip Truncated to 3 octets ipv6_address Device.ipv6 Truncated to 6 octets inventory_source_user_id User.id Blank Fields Added to LMT=1 Bid Requests In addition to the changes made to fields listed above, the following fields will be added to all records with  LMT=1 : Field Value user_id_hashed N/A ip_address_hashed DeviceExtensions.ip_hashed ipv6_address_hashed DeviceExtensions.ipv6_hashed LMT=1 Limitations Targeting Limitations Audience targeting is blocked. Precise geo-targeting, such as latitude/longitude and IP address targeting, is blocked. Logging and Macros Raw personal data is not available in logs. Device ID, geo, and user ID macros will not resolve in creatives or logs. Campaign Performance These limitations will not affect how campaigns behave, as targeting limitations are enforced at the platform level.