Symbols of the DEC, CURR, INT, and QUAN data types are normally formatted with a "thousands" separator character. The T option allows you to omit this separator character.
&symbol(T)&
The EKPO-MENGE field contains the value 1234.56. The ABAP Dictionary definition specifies 3 decimal places and an output length of 17.
&EKPO-MENGE& -> 1,234.560
&EKPO-MENGE(T)& -> 1234.560