The way a vendor allows its customers to use its licensed products.
NLS can support many models of licensing. For example:
Non-concurrent connections in BorderManager
Server Connection Licensing (SCL) in NetWare 4 and NetWare 5
User Access Licensing (UAL) for Novell Cluster Services™ and NetWare 6
For information about the licensing model for the product that you use, refer to the product-specific documentation.