Input (grade 12): While it is officially termed "Rivest Cipher 4", the RC acronym is alternatively understood to stand for "Ron's Code" Rivest FAQ (see also RC2, RC5 and RC6).
Output (grade 9): While its official name is "Rivest Cipher 4", the RC acronym is also known to stand for "Ron's Code" Rivest FAQ (see also RC2, RC5 and RC6).