What parameters should I use ?
loopcd (for all analytics platforms including Adobe, Google or Piano Analytics)using the utm_content parameter in substitution is possible (only for Google Analytics)
URL template
LinkedIn Ads does not allow dynamic tracking templates , so if you want automatic attribution matching, the Ad ID number must be hard coded in the URL parameters.You can use our native matching function . To use our automatic matching function, put exactly in the UTM parameters the names of the campaign, adgroup & ad with one element per parameter. Example : name of the campaign in the UTM campaign, name of the adgroup in the UTM keyword and name of the ad in UTM content.
Shoud I use both loopcd & utm_content ?
No, choose only one of those and stick to it.