clandestine churches
... that Catholics in the Dutch Republic were allowed to build clandestine churches as long as they were not visible to Protestants?
... that Catholics in the <a href="./Dutch_Republic" id="mwHtc" rel="mw:WikiLink" title="Dutch Republic">Dutch Republic</a> were allowed to build <b id="mwHtg"><a href="./Clandestine_church" id="mwHtk" rel="mw:WikiLink" title="Clandestine church">clandestine churches</a></b> as long as they were not visible to Protestants?