Show Lower Error X - whether the lower X errors must be displayed. 
Show Upper Error X - whether the upper X errors must be displayed. 
Size X - the size of the X error bars (upper and lower).

Show Lower Error Y - whether the lower Y errors must be displayed. 
Show Upper Error Y - whether the upper Y errors must be displayed. 
Size Y - the size of the Y error bars (upper and lower).

Show Lower Error Z - whether the lower Z errors must be displayed. 
Show Upper Error Z - whether the upper Z errors must be displayed. 
Size Z - the size of the Z error bars (upper and lower).

Error Bar series always support the Y and Label data point values, lower and upper Y error bar values are regarded if Show Lower / Upper Error Y is checked. If the Combo Chart Subtype is set to XY Scatter, the series will also accept X, Upper Error X and Lower Error X data point values. Similarly when the Combo Chart Subtype is set to XYZ Scatter the available data point value will be extended with Z, Upper Error Z and Lower Error Z data point values.