A person who is subject to a decision by the Federal Court, an individual whose citizenship is being revoked on the grounds of being a member of a foreign armed force that is engaged with the Canadian Forces in armed combat, if the Federal Court makes a decision to revoke citizenship on that basis, such a person would be barred permanently from applying for Canadian citizenship on the basis of the seriousness of the circumstances that gave rise to the revocation in the first instance.
On April 28th, 2014. See this statement in context.