PK - Primary Key NN - Not Null BIN - Binary (stores data as binary strings. There is no character set so sorting and comparison is based on the numeric values of the bytes in the values.) UN - Unsigned (non-negative numbers only. so if the range is -500 to 500, instead its 0 - 1000, the range is the same but it starts at 0) UQ - Create/remove Unique Key ZF - Zero-Filled (if the length is 5 like ..