Energy law and grids

German statutes rarely say muss. They say hat … zu and ist … zu, and the verb that shows the pair best in this field is dulden, to have to put up with something. Der Eigentümer hat die Leitung zu dulden: haben with zu and the infinitive lays a duty on the subject, exactly as muss dulden would, only in the register of the law. Swap in sein and the sentence turns passive: die Leitung ist zu dulden says the line must be tolerated and names nobody at all. Outside a regulation the same ist … zu often means can rather than must — das ist nicht zu ändern, nothing can be done about it — so only the context decides. In a letter from a grid operator it is always the duty, which is why der Zähler ist zugänglich zu halten is an instruction and not a suggestion.