Create a custom financial dimension
To create a user-defined financial dimension, go to General ledger > Chart of accounts > Dimensions > Financial dimensions. In the Use values from field, select Custom dimension.
You can specify an account mask to limit the amount and type of information that users can enter for dimension values. You can enter characters that remain the same for each dimension value, such as letters or a hyphen (-).
You can enter number signs (#) and ampersands (&) as placeholders for characters that change whenever you change a dimension value. Use a number sign (#) as a placeholder for a number and an ampersand (&) as a placeholder for a letter. The field for the format mask is only available when you select Custom dimension in the Use values from field.
For example, if you want to limit the dimension value to the letters "CC" and three numbers, enter CC-### as the format mask.