After reading your article from April 2016 about alphanumeric IDs for stations in Tokyo, I have been trying to do route searches using both the three-letter station codes and the alphanumeric station IDs with little success. On one website, TYO and UEN weren't recognized, but SGW and KWS were. Then, when I search for JY17 (Shinjuku) to A13 (Nihonbashi, Asakusa Line), a list of four stations popped on the latter, including Arashiyama Station in Kyoto (also A13). JR to JR works OK, for example JY10 to JK10.
My question is, are there any tips or recommended apps or websites for a foolproof route search in Tokyo? For example, directing a client to go to "G05" is a lot easier than spelling out Akasaka-Mitsuke, especially when they are coming from KS41 (Narita Airport Station T2). Or are the non-JR lines just a hopeless problem?