<P>The exception or limitation provided for in this Directive for the sole purpose of illustration for teaching should be understood as covering digital uses of works or other subject matter to support, enrich or complement the teaching, including learning activities. The distribution of software allowed under that exception or limitation should be limited to digital transmission of software. In most cases, the concept of illustration would, therefore, imply the use only of parts or extracts of works, which should not substitute for the purchase of materials primarily intended for the educational market. When implementing the exception or limitation, Member States should remain free to specify, for the different types of works or other subject matter, in a balanced manner, the proportion of a work or other subject matter that can be used for the sole purpose of illustration for teaching. Uses allowed under the exception or limitation should be understood to cover the specific accessibility needs of persons with a disability in the context of illustration for teaching.</P>