I have a question. The way I understand the message procedure as written on Dirk's and EWC's site, key settings were issued according to month and day. But I noticed on the historic message headers there is no day time group which tells the reciever what day the message was sent. So would I be correct if I said the kenngruppen are used to indentify the DTG of the key settings used? Was it permitted to have more than four parts to a message? If so, what was done about the fact there are only four 3 letter groups to choose from? Forgive me I am really really new to this.