NJA 2005 s. 142, 164 and 165.
Hänvisas från p. 2 (s. 416)
2.Placing a burden on one of the parties can solve problems of uncertainty. Thus, when uncertainty refers to facts, applying a principle of burden of proof may solve the problem. If a party cannot discharge its burden of proof for certain facts, the award must not be based on those facts. Problems of interpretation can be solved in a similar way by placing a burden on one of the parties. If a legislative provision or a precedent requires that a certain type of view of a contracting party can only be accepted if it has been made expressly, this requirement creates a presumption in the other party’s favor (tolkningsföreträde) in cases where the wording causes problems of interpretation. Sometimes the burden to clarify or to prove are mentioned as two alternatives, for instance where it is asserted that a contract between two parties creates a right for a third party, if it is proved or if it is made clear in the contract.s. 416