Delimitation from other bilateral juridical actsAnother problem connected with gratuitous contracts is their delimitation from other juridical acts. Let us start with the simplest case: gratuitous contracts and precarium. In older literature, precarium was defined as a relationship where the client (precario accipens) could ask the patron (precario dans) to let him use that patron's chattel. The precario dans could request the return of said chattel at any time-this differentiated precarium from commodatum (a gratuitous loan for use). Later precarium was defined as a gratuitous relationship arising from the rules of politeness or hospitality. For instance, whenever we are guests at somebody's house, we use our host's furniture, silverware, and sometimes even a room and bed with no overt contractual formality for this. The relationship is therefore purely factual, and in many cases the accipens is not protected by law. Some systems maintain precarium as part of their civil law. Others have abolished it and, at best, allow the use of the commodatum rules by analogy. The limits between precarium and gratuitous contracts remain somewhat blurred, and the legal nature of a relationship has to be determined in each case separately.Gratuitous contracts, as mentioned above, are characterized by a lack of consideration or any reciprocal treatment. However, in many cases that seem prima facie gratuitous, there is some kind of 'payment,' either directly or indirectly. This does not mean exactly that the contract stops being gratuitous, but rather that we have to decide if such 'payment' constitutes a consideration or reciprocal treatment. The most basic case is donatio sub modo-a donation where the donator obliges the donee to act in a specific way without making anyone a creditor. This does not make the donatio sub modo an imperfect obligation. It is the donator and sometimes a public authority who can demand that the donee act as stipulated in the donation contract. In this case there is no creditor-debtor relationship, but there is a way to force the donee to act as specified in the contract. Generally, the courts will be inclined to use the sub modo clause to assess various donations with additional burdens placed on the other party.On the other hand, in some cases it is doubtful whether we really have a gratuitous contract and not some kind of a commercial relationship. For instance, we have no doubts that if, say, MOL, Orlen, or Shell give money to a sports association in exchange for displaying their logo, or change the name of the football stadium to 'ORLEN ARENA,' it is not a donation but a sponsorship contract. Let us now change the setting and assume that a large corporation funds a chair at a university (say, the 'BigBusinessInc Chair of Maritime Studies') or gives a large sum of money to the same
