1. A computer-implemented method for selectively providing Notice To Airmen (NOTAM) notifications to a crew of an aircraft, the computer-implemented method comprising: receiving, by a processor, a plurality of NOTAMs; determining a target phase of flight associated with the aircraft, from a plurality of predefined phases of flight; determining a relevance for each of the plurality of NOTAMs, according to the target phase of flight, based on a plurality of relevance rules, each of the plurality of relevance rules assigning relevance based, at least in part, on the plurality of predefined phases of flight; providing, by the processor, a notification of one or more NOTAMs according to the relevance for the target phase of flight; and assigning a relevance code to a plurality of NOTAM subject codes for each of a plurality of phases of flight, wherein the relevance for each of the plurality of NOTAMs corresponds to the relevance code associated with a NOTAM subject code of each of the plurality of NOTAMs; wherein each relevance code comprises the relevance of the NOTAM subject code to a plurality of flight segments of a planned flight route such that determining the relevance for each of the plurality of NOTAMs according to the target phase of flight comprises retrieving the relevance code corresponding to the target phase of flight and determining the relevance for each of the plurality of NOTAMs according to the corresponding relevance code, and wherein providing the notification of one or more NOTAMs according to the relevance for the target phase of flight comprises determining one or more types of notifications to provide according to each relevance code and providing the one or more types of notifications; wherein the relevance code comprises a multi-letter code, the multi-letter code including a plurality of letters, each of the plurality of letters associated with one or more flight segments, of the plurality of flight segments, of the planned flight route, and each of the plurality of letters comprising an indication of relevance of the NOTAM subject code to the corresponding flight segment of the planned flight route for the target phase of flight.
4. The computer-implemented method of claim 1 , further comprising: determining a NOTAM status for each of the plurality of NOTAMs; determining a notification activation code for each NOTAM status; and modifying the relevance code according to the notification activation code.