Abstract: A propagation server for facilitating propagation of recorded information between first-party data structures associated with different domains, the propagation server arranged for data communication via a network with web browsers of client devices, wherein the propagation server is associated with a propagation domain being a web domain, wherein the propagation server is configured to: receive a first request from a first web browser, said first web browser associated with a first client device, wherein the first request identifies a first domain being a web domain different to the propagation domain; determine, via data communication with the first web browser, whether a propagation data structure, being a first party data structure associated with the propagation domain, is present on the first web browser; in a case where the propagation data structure is present: determine an identifier from information stored with the propagation data structure; generate first propagation information in dependence on t

Abstract: A method for recording information within first-party cookies on a web browser, including propagating recorded information from a second cookie associated with a second domain to a first cookie associated with a first domain, wherein the first cookie and the second cookie are each first-party cookies, such that a first web resource of the first domain and a second web resource of the second domain each have access to the recorded information via its associated first-party cookie, and corresponding server and system.