CFIELDNAME can be read as currency field name. When you have in your internal table a field that represents the currency for the amount stored in a field kept under FIELDNAME in field catalog, then you should place its name here. The output of the cell will be then based on a currency key kept in the same row of the internal table, in the corresponding field. 

In the sample program ZDEMO_AIN_CL09 you can see that I passed to the filed catalog CFIELDNAME as ‘CURRENCY’ which is one of the columns of table SFLIGHT, that keeps currency key for field PRICE.


Figure 19 ZDEMO_AIN_CL09 CFIELDNAME filled

 As data in this table didn’t contained a line with JPY, I’ve changed in SE16 the currency key for one of the rows in order to show you the difference in output.


Figure 20 Changed entry of SFLIGHT table in SE16


As the output of the PRICE column depends now on the currency key stored in CURRENCY column, then you can see in the first row that the price is without decimal places, as it should be for Japanese Yen, and in the next rows as we have USD then we see two decimal places.

Figure 21 ZDEMO_AIN_CL09 results