The present disclosure is directed to determining a unique content instance identifier (CIID) for each content item handled in a content management system. The content item has been received from one of a plurality of content providers and/or content delivery channels and has been identified by said one of a plurality of content providers with an original content identifier within an original identification scheme. A data structure of the CIID is defined depending on the original identification scheme, the data structure including a first, a second and third part, wherein the size of at least one of the second and third parts depends on the original identification scheme; stores a code in the first part.