1. Although this rule was made in France its labels are in German - though it is based on a system developed in Basel (Switzerland). This is the first rule reinforced concrete I have come across which was not German.

2. The rule is much simpler than other rules of this type that I have come across having just three special scales on the front.  These are:
-   armierung : reinforcement.
-   Innerer Hebelarm - inner moment.
-   Spannungsverhältnis - stress ratio.

3. The rule is used for a modular ration "n" (between steel in tension and concrete in compression) of 10.