Apple has begun rejecting apps that involve cookie tracking, according to a report by TechCrunch.

No, not apps like Girl Scout Cookie Finder, which lets you track down the nearest box of Girl Scout cookies in your area. Rather, the apps in question are those that engage in tracking cookies or packets of online data for marketing purposes.

As noted by TechCrunch, cookie tracking is …

… essentially a technology that’s a holdover from the desktop web era, where cookies have been used for some 15 years. On mobile, the process generally involves HTML5 local storage, because “mobile cookies” aren’t technically the same as those on the desktop. “Within local storage, an app developer can drop a token – an ID, if you will – and then retrieve it later. In this regard, it works like a cookie, so the industry frequently uses it and talks about it like it’s a cookie,” explains Craig Palli, VP of Business Development at mobile app marketing firm Fiksu, which works with developers on user acquisition efforts.

Apple’s recent app rejections suggest that it may soon be requiring developers to adopt its own Advertising Identifier technology instead of cookie tracking.

Introduced in iOS 6, Advertising Identifier replaced Apple’s Unique Device Identifier (UDID) implementation for marketing purposes.

UDID was once the tool advertisers used by developers to learn customer patterns. But on account of UDID leaks and privacy issues, Apple replaced it with the Advertising Identifier.

Advertising Identifier is said to be more private and “non-personal and non-permanent in nature.” What’s more, customers have the option to turn it off, by going into the Settings app and tapping General > About > Advertising.