19.6.2. Format masks

When a format mask is encountered, a check is executed to see if the mask follows an internal form, for example, format1, accounting_float, etc. (See jxl.write.NumberFormats.)

If the mask is not part of the internal list, it is treated as a custom mask (for example, 0.00), and automatically converted to the closest match. (See java.text.DecimalFormat.)