Charles Arthur wrote on the Guardian tech blog about a new code for civil servants interacting on the web:
Principles for participation online
1. Be credible
Be accurate, fair, thorough and transparent.
2. Be consistent
Encourage constructive criticism and deliberation. Be cordial, honest and professional at all times.
3. Be responsive
When you gain insight, share it where appropriate.
4. Be integrated
Wherever possible, align online participation with other offline communications.
5. Be a civil servant
Remember that you are an ambassador for your organisation. Wherever possible, disclose your position as a representative of your department or agency.
Change that last one to "Be a librarian" and you've got a nice little set of guidelines...