Quick Question about Notation

[IWantGoldfish]

Hey guys,
I am just beginning to learn f2l and i have an understanding of the notation, however in some of the algorithms they have a 180 degree turn prime ex: R'2
I am not sure how to execute that so help would be appreciated
Ty

 

[MineKB]

You do it like an R' but a 180 degree turn. An R2 is just an R but a 180 degree turn.

 

[Hypocrism]

In some algorithms, it's faster to do an anticlockwise 180degree turn than a clockwise one, because of the position of your right wrist. It can remove the need for a regrip for example. The end result of an R2 and an R'2 is the same, but notating it can help somebody find a faster way to execute.

EG:

U2 R2 U2 R' U' R U' R2 (do the inverse to set up this F2L case) would (for me) be notated as: U2 R2 U2 R' U' R U' R'2, because I execute the final R2 anticlockwise since it puts my hands back near the neutral position without a regrip.