how to tell if a Blu Ray is region free?

[LoneWolfCub]

i may have some dumb questions. but how would i tell the diffrence between region free and region 2 Blu Ray just from the front cover? i am looking for several Blu Rays i cannot find American releases for because they are outragous. i found the last 2 seasons of Homeland on amazon. under 20. in Blu Ray. but it says region 2. but they look exactly like my region free Blus. i have 3/4 Blu Rays region free. and i cannot tell the diffrence all mine has the 15 or 18 on each side. as do the pictures on Amazon. i also found the region free blus on ebay but a little higher than what i want to pay. . but they look exactly like the ones that say region 2 on amazon. i have a US PS4. as my Blu Ray player. btw.