While you probably do not understand this name we shall explain this first:
"MAF-fe=MAF(adjectives sometimes have meaningless extensions, fe, in dutch)

So "de MAF-fe tuinman" is a convention inspired by mr Gardener's idea, to use the 1NT overcall of an opening bid as a multi-way bid for hands that otherwise cannot be described adequately in a particular system.

In MAF we have jump overcalls for weak 1-suiters, normal overcalls for normal 1-suiters, the Ghestem convention for weak 2-suiters and the take out double for strong 2-suiters. MAF does not have yet proper overcalls for very strong hands.

To make the "overcall complex complete", the properties for the two-way "de MAF-fe tuinman" must be:

The partner of the 1NT overcaller must answer. He has two possibilities:

The rebids from the "MAF-fe TUINMAN caller" are never forcing. If his partner holds >=10 hcp's he must try to reach the game og course.