Grid Spacing: This is the size of each square.
Place Labels
In each cell: check this to add text to the grid location representing each cell.
Along edges: check this to add labels along the edges of the grid.
First X label: this is the first number or letter for the horizontal axes. You can start at any letter or number. Letters count up A-Z, then AA-AZ etc.
First Y label: this is the first number or letter for the vertical axes. You can start at any letter or number. Letters count up A-Z, then AA-AZ etc.
Text equivalent: ADDGRID