12.1. No union having changed its affiliation, whose name at the time of that change included one of the expressions mentioned in section 12, may carry on its operations under a name including that expression for a period exceeding sixty days from the coming into force of the change of affiliation, except a union contemplated in the first paragraph of section 12 that has affiliated with a federation contemplated in that paragraph, or a union contemplated in the second paragraph of section 12 that has affiliated with a federation contemplated in that paragraph.