Why is it that these two formulas automatically copy down to a new row that I create in my table (by pressing TAB in the bottom right hand cell).

=IF(E31<>"",(D30+1),"--")

and

=IF(U31="", "--",
IF(OR(U31={"$","€"}),VLOOKUP(E31,[RefHidden_120622.xlsm]Ref!$BY$5:$CB$60,MATCH(U31,[RefHidden_120622.xlsm]Ref!$BY$3:$CB$3,0)),
"1.00"))

However, this one does not:

=IF(F31="","--",
IF(OR(F31="BF",F31="BD"),X10,0))

Thanks.