Good reference for that: https://jameshfisher.com/2016/11/27/c-k-and-r/ https://jameshfisher.com/2016/11/27/c-k-and-r/ This was also used to implement variadic

Good reference for that: https://jameshfisher.com/2016/11/27/c-k-and-r/ https://jameshfisher.com/2016/11/27/c-k-and-r/ This was also used to implement variadic functions like printf before varargs, see https://retrocomputing.stackexchange.com/a/20517 https://retrocomputing.stackexchange.com/a/20517