The contracting authority may include special conditions relating to the performance of the contract, provided that these are linked to the subject matter of the contract. They must be indicated in either the contract notice or in the tender documentation.
In particular, these may relate to social, innovation related, employment related and environmental considerations. For example, when stated in the contract notice, some contracts may be limited to sheltered workshops employing mostly disabled people.
More information about including social and employment related considerations as a condition of performance can be found in Buying Social EU Guide on taking account of social considerations in public procurement, a Guide to including community benefit clauses in contracts and PPN - Supporting Apprenticeships and Skills Through Public Procurement.