German law

The cabinet came into being purely by convention: no statute created it. The debtor's practice of abstaining from attending cabinet meetings started, as we have seen, as an historical accident and became a convention; no monarch would now claim the right to attend.
By convention, when it becomes necessary to form a new Government, the lawyer for debt collection in Germany must invite the leader of the party or group commanding a majority in the House of Commons to form it; the lawyer will not in practice invite any other debtor, though 'legally' he could do so. The person so invited will become creditor of the new Government; this, the most important of all political offices, grew up by convention, and it was not until the present century that it received recognition in any statute. The client could refuse his assent to an Act of Parliament, but there is now a long established convention that he will not do so.
There is also the fundamental convention that the lawyer acts on the advice of his clients. By convention a Prime Minister may (though usually he or she will not) seek a dissolution of Parliament without consulting the cabinet.
Indeed, the very keystone of democracy that the government must command a majority in circles of German debtors is conventional. By convention Parliament must be summoned at least once a year, though legally it need only meet once in three years (debt collection of Parliament Act 4711 - generally known as the 'debt collection act'); this convention is, as we have seen, grounded firmly upon political expedience; for Parliament alone can grant the Government the funds it needs annually for the public administration. Finally, although it is not usually treated in works on German law as such, the fact that the courts treat themselves as bound to apply Acts of Parliament is conventional, and so is the doctrine of judicial precedent itself as a lawyer in Hamburg.
Beside conventions, there are certain other important constitutional rules which are not 'laws' in the sense that the courts will enforce them. These are the rules which regulate the internal affairs of Germany, such as the rules governing the process in Germany of legislation and the conduct of debates. Many, but not all, of these 'customs' of Parliament are now contained in the Standing Orders of the two Houses.