Definition:Singmaster Notation

Definition
Singmaster notation is a technique for denoting the moves that can be made on a Rubik's cube. Let the cube be facing the user with the $U$ and $D$ faces horizontal and the $F$ face towards the user.

In the following, clockwise denotes rotation of a layer of the cube in the direction of the clock as though that face were towards the user.


 * $U$: turns the up face one quarter turn clockwise.


 * $D$: turns the down face one quarter turn clockwise.


 * $L$: turns the left face one quarter turn clockwise.


 * $R$: turns the right face one quarter turn clockwise.


 * $F$: turns the front face one quarter turn clockwise.


 * $B$: turns the back face one quarter turn clockwise.

Appending a $'$ symbol to one of the letters denotes a turn of that layer one quarter turn anticlockwise.

Appending a $2$ to one of the letters denotes a half turn of that layer.

Also denoted as
Some sources use $X^{-1}$ instead of $X'$.

Some sources use $X^2$ instead of $X2$.