Do you know if this expression is written in Sap script or another language?
If so, what does this expression ask for?
AC = Account
CLASS=P = P&L accounts
FL = Flow
DP = Data entry period
PE = Period
Y99= year to date
{AC in (CLASS=P) ; FL=PER} = IF([DP=+0.01] ; {FL=Y99 ; DP=+0+00 ; PE=+0+00}- {FL=Y99 ; DP=+0-01 ; PE=+0-01})