At the start of each packet are binary flags. Some flags appear only if certain flags are marked as 1 or 0 near the beginning. Flags are used to designate data presence in a packet. Flags change the way packets. The additional data & flags change the start position of different data sections such as the packet's content data, certificate, and puzzle. Typical flags like including a certificate in the connection establishment phase. The puzzle flag is another common flag that can present at any point during connection establishment or the life of the connection.
Currently the two main flags are "Is a certificate present" and "Is a puzzle present". If the flags are set to 1 it indicates the presence of that data set. For example, if the puzzle flag is set to 1 it indicates that a puzzle is present in the packet and it must be solved in order to continue communication.
Another type of indicator flag are data sizes. Before the start of any content data there is a 3-4 digit number which indicates the size of the next or upcoming data section. This is used to signify the start and end of a data section.