Why? Because physical DVDs in Region 5 sometimes have different street dates. In the past, studios have sent "workprint" or "final cut" versions to these regions earlier for dubbing and subtitling. Consequently, a leak or an early retail sale led to the entire season being available as "S15 R5" weeks ahead of schedule.
: The former Chief Constable who often provides intellectual support or conflict for Murdoch. murdoch mysteries season 15 r5
In the world of digital releases, "R5" stands for . This refers to a DVD (and sometimes digital master) released in Region 5 territories, which include Russia, Ukraine, India, most of Africa, and parts of Eastern Europe. which include Russia