The Canadian Union of Postal Workers may go on strike Friday. On Tuesday, the union gave a 72-hour strike notice. This means that Canada’s publicly owned mail service will slow its work — or potentially grind to a halt. Here’s what it could mean for Canadians.

The Canadian Union of Postal workers has given notice of a strike. In a release Tuesday morning, Canada Post said it expects a “rotating” strike, which means some postal workers will still be on the job at various times. It wouldn’t be an all-out work stoppage, but it also wouldn’t be business as usual.