Friendly codes are three-letter codes serving as a password for a planet's or starship's computer systems. Two objects having the same friendly code appear friendly to each other.
Some friendly codes activate special missions for the planet or the starship. PHost aims to move away from using friendly code for these cases, towards extended missions and commands, but the friendly codes are still supported.
Friendly codes can contain any printable character from the ASCII set. This includes all latin letters in upper and lower case, numbers, and many punctuation characters, but disallows control characters and high-ASCII characters such as umlauts, cyrillic letters, etc.
