The Church of Scotland (or Kirk) is the largest religious denomination in Scotland, however, unlike the Church of England it is Presbyterian and (since 1921) not a branch of the state, with the Sovereign holding no formal role in the Church other than being an ordinary member. However, though the Kirk is disestablished, Scotland is not a secular polity. The Kirk remains a national church to which the state has special obligations; it is conventional that the monarch, who is head of state, must attend the Church when she visits Scotland, and they swear in their accession oath to maintain and preserve the church. The state also gives numerous preferences to the Church of Scotland and Catholic Church, particularly in education. The blasphemy law has not been abolished in Scotland, though it has fallen into disuse. Non-religious couples can have a civil wedding with no religious elements, and humanist weddings have been legally recognised since 2005, and enshrined in Scottish law since 2017. Collective worship makes prayer and worship of a Christian character mandatory in all schools, but parents can remove their children from these lessons, though sixth formers have no right to opt out.