Detailed instructions for working a group puzzle of type 'Zack'

This is a signature puzzle named 'Zack'

The 4 elements in each group of this type of puzzle are: Z, A, C, and K.

Every group in the puzzle must contain exactly this set of elements.

Each row is a group numbered as shown in this Zack figure.

In a Zack puzzle, each row is a group numbered as shown in the figure above.

Each column is a group numbered as shown in this Zack figure.

In a Zack puzzle, each column is a group numbered as shown in the figure above.

Each 2x2 square is a group numbered as shown in this Zack figure.

In a Zack puzzle, each 2x2 square is a group numbered as shown in the figure above.