UIAA Scale of Difficulty for rock climbing

This scale has been adopted by the International Mountaineering and Climbing Organisation, which groups dozens of national mountain sports federations.
It is divided into 11 grades expressed in Roman numerals.
The first 4 UIAA grades correspond to the first 4 grades of the French system.
The table below only shows the first 3 grades of the two scales. Greater difficulties are not present in my tours.

UIAA scale French system Description
I 1 It is the easiest kind of scramble. Frequent use of hands is required to support balance and hand and foot-holds must be trusted.
II 2 Here real climbing begins, that requires the movement of a limb at a time and a proper setting of the movements. Holds and supports are still abundant
III 3 The rock structure, already more steep or even vertical, offers holds and supports the rarest and can already require the use of force.
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