The addendum is in a file next to the article:
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"I acknowledge that even my personal life (…) is to be in conformity with the 10 Commandments. (…)
I agree that it is my duty, to the best of my ability, to believe, teach/administer and live in accord with what the Catholic Church holds and professes."
The only part where the text is addressed only to the Catholic teachers is where it says that they should attend Mass each Sunday. All the rest is addressed both to Catholics and non-Catholics.
The article says that the contract addendum has been distributed to the 200 educators at 11 Catholic schools who are formally employed by the bishop. 25 percent of the teachers are non-Catholic.
As to the sincerity of those who will sign the document, the article says:
It seems that Bishop Vasa has no idea how many teachers taught Communist doctrine “with zeal and enthusiasm” in the Communist countries, while disagreeing with it “in the privacy of their heart”. They did that to keep their jobs.