Indeed Tom, why not ;o)

PS:
I remember there was a way to add a "sort-of-comment" in a formula...
without affecting the formula.

Something like eg.:
=If(counta(rng)=0,"Blank","Not Blank") *T("This is function returns
true or false when range is empty")
or
=If(counta(rng)=0,"Blank","Not Blank") +Text("This is function returns
true or false when range is empty")
or
.... I have no idea anymore how it was ...