Usage patterns
〈事〉はタブーだfor something to be taboo
In this country, talking about politics is taboo.
タブーを破るto break a taboo
He spoke out, breaking a social taboo.
タブーに触れるto touch on a taboo subject
That question touched on a taboo subject.
〈事〉をタブーとするto treat something as taboo
That topic is treated as taboo at the workplace.