We subscribe European XBO trades from ELEKTRON via RFA API. In our XBO feeds, we use ALIAS to identify exchanges. For example, LSE for London Stock Exchange, BTE for BATS. However, in some of XBOs, like Helsinki, other than other aliases, we encounter the ALIAS that is set to "NMP". It seems that the trades are OnBook Dark trades but anybody knows what "NMP" stands for? thanks.