In my opinion ship's friendly code can only be changed by it's owner. Even Super Spy Deluxe only affects planet's friendly code.
It's however possible to get "gsX" (or "mdX", "NTP", etc.) friendly code when you randomise ship/planet friendly code. By "randomise" I mean when you click that box where friendly code is shown (so, not clicking "Friendly"-button where you change it manually). Maybe you accidentally clicked it?
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