Do I understand correctly that the encoding is only done to obfuscate the URL from automatic spam filters? So the choice of Morse code was arbitrary - any othe

Do I understand correctly that the encoding is only done to obfuscate the URL from automatic spam filters? So the choice of Morse code was arbitrary - any other simple substitution scheme could have been used to the same effect (maybe very common ones like base64 encoding or ROT13 are already being checked for?).