An Authorization to Return to Canada or ARC is a particular permission that a foreign national will need to legally return Canada if they were issued a removal order. “Being asked to leave” can refer to a number of measures the Canadian government takes to ensure the departure of a particular foreign national. Depending on the measure taken, an ARC may or may not be required. There are 3 types of removal orders:
Departure Order
Exclusion Order
Deportation Order
If you were deported because of criminal inadmissibility you are most likely have to apply for either Criminal Rehabilitation or a Temporary Resident Permit (TRP) to enter Canada legally.