Lien refers to the real right on movables. On the other hand, there is an opinion that the lien on demands (claims) belongs to the contract law. Lien represents a subsidiary right and it serves to secure the main claim. Lien can exist over movable property, immovable property and rights being created on the basis of legal work or court decisions. The Law of Contract regulates the commitment of claims and other rights as a special kind of a pledge coming from the pledge on claims or other rights itself. . A separate subspecies is advocating the claims of the securities. The contract law provides for the duty to preserve claims. It says that a pledge is obliged to take certain measures necessary for preserving a pledge (e.g. protest bills, submitting a bill lawsuit or suggestion for the execution on the grounds of a valid document in order to stop the flow of obsolescence etc.). A creditor acquires a lien on the claim written on a security to a bearer when it is handed over to him. Pledging of securities receivable upon the order is going to be carried out by endorsement in which it is indicated that the pledge was made to the spout. When the claim becomes due and payable, the pledge is supposed to charge it. Unlike the mortgage and pledge where the principle of officiality prevails and which are usually realized at the court, in advocating the claims, the collection was left to the lien creditor. The provisions of the Law on Pledge Right of Movable Assets registered in the register are applied to the pledge of intellectual property rights. The pledge on such rights will be entered in the register of the Institution responsible for the intellectual property, e.g. in the trademark register of register patents. By the Law of Contract it has been established the statutory lien in favor of the commissioners of certain rights or claims.