The subscription service allows a client to subscribe either to selected event scenarios or to the full event context. This supports both targeted event consumption and broader event monitoring according to consumer needs. The AIXM 5.1 data and digitalNOTAM are returned together with the referencing time slice, which contains the actual feature change (TEMPDELTA or PERMDELTA) and the underlying BASELINE of the feature change. This allows clients to receive the full scope of the DNOTAM.