Another example is the so-called "sole" license. Common wisdom holds that a sole license, as distinguished from an exclusive license, allows the licensor to make use of the licensed IP, in addition to the right of use granted to the licensee. Here as well, however, there does not appear to be an explicit statutory basis for the status of the sole license, as opposed to an exclusive, or non-exclusive license. The source of the sole license is equally uncertain.
that arise with respect to each of them, is the underlying fact that none of them is creature of statute or similar legislative diktat. This fact has a powerful implication, not always appreciated, namely that there is no single, common font of meaning for these terms. This further means that when one encounters these terms, he or she should not feel embarrassed in admitting a certain sense of unease in fashioning their meaning within the context of the specific agreement. Custom and widespread acceptance have made them part of the licensing and technology transfer lexicon, but this has not replaced the need for vigilant lawyering in their particular application.