PLL Na
The algorithm, how to recognise it and how to practise it without cheating.
Recommended algorithm
R U R' U R U R' F' R U R' U' R' F R2 U' R' U2 R U' R'21 moves
How to recognise it
Looking straight at any side, its right two stickers form a block and its left corner is the opposite colour. Any angle works.
Practise Na now
Random-state scrambles, a timer and spaced review. Free, on the web and on your phone.