You can transfer the economic rights of a unique and original work - under a license or a protocol.
A license means that you grant the client the ability to dispose of your work for a certain period of time, in this case, 15 years. After this period, the client or customer loses the right to dispose of the work.
A non-exclusive license leaves you free to continue selling the completed product to other clients (e.g., photos, programs and applications, add-ons to graphics programs, etc.).
The granting of a license in Useme and its scope are defined in the terms and conditions (in Article 7) and, unlike in the case of transfer of copyright by protocol, does not require the preparation of additional documents.