50. A public body may require a quality assurance system, including the ISO 9001: 2000 standard, or a specification relating to sustainable development and the environment for the carrying out of a contract. The public body must specify the requirement in the tender documents.
If such a requirement unduly reduces competition, the public body must allow any service provider to submit a tender and grant to a service provider that fulfils the requirement referred to in the first paragraph a preferential margin not exceeding 10%. In the latter case, the price submitted by such a service provider is, for the sole purpose of determining the successful tenderer, reduced by the preferential margin, without any effect on the price for contract awarding purposes.
The percentage of the preferential margin to be applied must be indicated in the tender documents.
In the case of a contract whose quality evaluation is based solely on the quality measurement, the public body must ascertain that there is enough competition to allow the first paragraph to apply.