Answering a bidder clarification
Every answer changes the competition. That single fact governs the process.
The rule that overrides everything
An answer given to one bidder is published to all bidders, with the question anonymised. There is no such thing as a quiet clarification, and giving one is a challengeable irregularity.
Answer only from the documents
Quote the specification, the instructions or the evaluation criteria and cite the section. If the documents genuinely do not say, that is a gap — it goes to the procurement lead, who may need to correct the documents for everybody.
Never expand the specification in an answer
If the answer would add a requirement, it is an amendment. It goes through the amendment process with a deadline extension if warranted.
Always record
Question, date received, date answered, the answer, and the date published.
Never
Indicate a preferred approach, comment on another bidder, confirm receipt of a submission outside the process, or answer after the clarification deadline without extending it for all.