Use formal correspondence means (eg. signed letter with CERN’s letterhead) for every communication concerning milestones being formally reached or contractual obligations, defining clearly CERN’s instructions, identified non-conformities, requested deadlines, safety aspects, etc. 

Warning: 

Keep all records in writing. Document non-conformities via a NC registry. This will help settle future dispute. In the frame of contractual disputes, communication must be handled by the procurement Officer. Please refer to section 3.2.5 ‘Dispute settlement’ below.

Link: CERN’s Letterhad template.

Acknowledge receipt of the letter and submit an answer within the requested deadline.

Warning: 

Should CERN’s letter only require an acknowledgement of receipt from the Contractor, CERN’s letter should include a provision such as: “You are kindly requested to return to CERN a signed copy of the present letter within five working days of its reception. Without any response from you within this deadline, the letter will be considered accepted.” Beware, a confirmation in writing shall be requested for any matters related to Safety.