Standard Terms
6 articles on this topic.
What your terms say takes effect only once they have become part of the contract and the individual clause holds up under German standard terms law. Whether they hold is decided in sequence, at four stages: negotiation, incorporation, transparency, consequence. When a clause falls, the statute takes its place.
Articles

Standard terms in B2B: freedom of contract is the exception
German standard-terms law catches every pre-formulated clause, between businesses as well, and it decides clause by clause. Why that governs your contracts, and where to read on.

Standard terms: template, generator, or lawyer?
Templates reflect the average, generators do not know your facts. Why generic standard terms fail predictably, what a lawyer does differently, and when a template is actually enough.

How to incorporate standard terms internationally
How standard terms become part of the contract in international business, and what happens when both sides’ terms collide (battle of forms).

As far as legally permissible? Not a good idea.
A contract clause with the rider “to the extent permitted by law” is invalid. In a forum-selection clause, this becomes a serious problem.

No oral side agreements exist. But they do!
The German Federal Court of Justice (BGH) ruled on the validity of the clause ‘No oral side agreements exist’ in standard terms.

No individual agreement
A pre-formulated clause stating that the parties have supposedly negotiated each term individually is counterproductive.