Q: What should I include in my resignation letter?

A: The more important question to be asking is what not to include, say the experts. 'Less is always more,' says Roy Cohen, a Manhattan-based careercounselor and executive coach. 'This is not the time to set the record straight. Know that it's a small world.' By leaving on the best note possible, you also keep open the option for a return to the company should your circumstances change.

Rather than airing your grievances with the company, you should set a positive tone from the start, says Marilyn Puder-York, a psychologist and executive coach in the New York metro area. One way to do this is to include a sentence or two at the top that shows your appreciation for the opportunity to work at the company and the experience it has given you.

Small courtesies are also important. This includes giving enough notice: a minimum of two weeks but preferably one month, says Ms. Puder-York, who has seen people give as much as six months, a move that she wouldn't recommend. 'You lose a lot of power and credibility in six months,' she says. Your preferred last day should also be included in the letter.

Both Mr. Cohen and Ms. Puder-York recommend that you don't list reasons for your resignation, no matter how tempting it might seem. 'Once you've made the decision to leave, the reasons are superfluous,' says Mr. Cohen. One option is to include the following sentence at the end of your letter: 'I would be happy to discuss my reasons for resigning as well as any particular support I can give you during the transition,' suggests Ms. Puder-York.

'Make the letter clear, direct and simple,' she says. 'You should always wait to give additional information in a verbaldiscussion. The letter ends up in your file. You don't know where it is going to go.'

At some companies, a formalresignation letter may not even be necessary, says Ms. Puder-York. But she still recommends submitting one, equating it with the increasingly rare written thank-you note. 'It is the smart, respectful thing to do, and it's a gracious thing to do if you do it well,' she says.