Bing announced a new solution to enable tracking across Apple’s Safari browser after they implemented Intelligent Tracking Prevention. Bing said “to help ensure that conversions continue to be reported accurately and in full across your Bing Ads campaigns, the auto-tagging of the Microsoft Click ID in ad URLs is now required.”
Here Bing Ads will automatically add a unique click IDs to the landing page URLs after a customer clicks your ad. The landing page URL may look something like this: www.contoso.com/?msclkid=123abc, Bing explained.
You can enable the auto-tagging of the Microsoft Click ID on the URL options page of the Shared Library by checking the box, “Add Microsoft Click ID (MSCLIKID) to URLs to allow conversion tracking.” This option will be selected by default when creating new conversion goals.
Here is a screenshot:
Ginny Marvin has more details over here.
Forum discussion at Twitter.