the problem
Having to write letters of recommendation for people with very dubious qualifications can cause serious legal troubles in a time when laws have eroded the confidentiality of business letters. In most states, job applicants have the right to read the letters of recommendations and can even file suit against the writer if the contents are negative.

the solution
Here is an arsenal of statements that can be read two ways: You are able to state a negative opinion of the ex-employees poor work habits, while allowing the ex-employee to believe that it is high praise. When the writer uses these, whether perceived correctly or not by the ex-employee, the phrases are virtually litigation-proof.

To describe a person who is extremely lazy:
'In my opinion,' you say as sincerely as you can manage, 'you will be very fortunate to get this person to work for you.'

To describe a person who is totally inept:
'I most enthusiastically recommend this candidate with no qualifications whatsoever.'

To describe an ex-employee who had problems getting along with fellow workers:
'I am pleased to say that this candidate is a former colleague of mine.'

To describe a candidate who is so unproductive that the job would be better left unfilled:
'I can assure you that no person would be better for the job.'

To describe a job applicant who is not worth further consideration:
'I would urge you to waste no time in making this candidate an offer of employment.'

To describe a person with lackluster credentials:
'All in all, I cannot say enough good things about this candidate or recommend him too highly.'