This is a common mnemonic, but it also has a common flaw, which is easily reached by application of a modicum of overthought: Both proxies always act as both se

This is a common mnemonic, but it also has a common flaw, which is easily reached by application of a modicum of overthought: Both proxies always act as both servers and clients; just to different sides, one in the direction of requests (forward), another against (reverse). At least that's where I end up every time I have to remind myself which is which.