Transform Orientation

In the Transform orientation pop-over it is possible to select and configure transformation orientations.

Default transform orientations are:

Global
Align the transformation axes to world space.
Local
Align the transformation axes to the selected objects' local space.
Normal
Align the transformation axes to average normal of selected elements.
Gimbal
Align each axis to the Euler rotation axis as used for input.
View
Align the transformation axes to the window.
Cursor
Align the transformation axes to the 3D cursor.
Add +

With the plus button a new transformation orientation can be created from the selected object.

Name
A name can be specified.
Delete X
It is also possible to remove these custom transform orientations.