BusinessObjects Board

Promp parameter in FH SQL

acc. to BO Help Portal, a prompt can have an optional attribute called “formula_expression”
as example is stated: @Prompt(‘Select the min date:’, ‘D’, , mono, free, not_persistent, , user:0, ‘currentDate() - 7’)
now I want to use this in a FH SQL, but I cannot do it successfully, this parameter just gets ignored, no default value is desplayed
what could be the reason?