In addition, the parties must have agreed, in a signed document, that the factory is a rental work. Works created before 1978 are subject to slightly different rules. The first and most obvious situation in which the employer holds the invention rights is when the employment contract officially confers invention rights. To be valid, the employment contract must be written and describe in detail the nature of the invention or include a sufficiently specific description of the invention. The conditions of assignment must not be grossly abusive. The latter criterion is described as a standard of scruples. Technically, the inventor can still assign rights to the invention to anyone, including employers, but not all states actually recognize orders under employment contracts unless the worker signs a state-certified written notification of its effects on his or her rights as an inventor. States requesting such notification include: 2.2. Allocation of developments. . .