A letter of recommendation is a letter from a supervisor, instructor, or similar authority figure which recommends a particular candidate for a position. You may also hear a letter of recommendation called a reference letter. Such letters are commonly required in college applications, and they can bolster applications for employment as well. A well-written letter of recommendation is uniquely customized to the person being recommended and the type of position the person is applying for, although it is also possible to see generic letters of recommendation which can be re-used.
The letter of recommendation has become such a common part of some application procedures that some colleges maintain a library of such letters in their student files. If Mary Jane, for example, requests a letter from Professor McNamara, the letter will go in her student file so that if she needs it again, she can request a sealed copy from the school rather than having to ask the Professor for a new copy. People may also be given universal letters of reference when they leave long-term jobs, as a gesture of good wishes from their former employers.
Requesting a letter of recommendation can be tricky. Generally, as soon as you know that you are going to need a letter of recommendation for something, you should ask the people who would be best suited to write the letter. Most requests should be worded in such a way that the recommender feels comfortable turning down the request if she or she does not have enough time, or does not feel that he or she could write an honest and accurate letter. In a request, people should be sure to specify when they need a response to accept or turn down the request, and when the letter itself is actually needed. To prepare for people who might turn down requests or turn in letters too late, it is a good idea to ask for more letters than you need; if all the requests are granted, it just makes your application look better.
Depending on the nature of the position being applied for, the applicant may be asked to turn in sealed letters of recommendation, indicating that he or she has not read the letters. This is designed to encourage honest responses from recommenders, and to ensure that the applicant does not quietly remove any unfavorable letters, although such letters are generally rare. If someone thinks that he or she would write a bad letter of recommendation, the responsible thing to do is to turn down the request.
When writing a letter of recommendation, recommenders should think about what makes the applicant unique, and what his or her strong points are. It's a good idea to mention how long the recommender has known the applicant, and in which content, as in “Mary Jane has been taking English with me for the last two years,” or “Joe Bob has been employed in my division for the last 10 years.” Referencing awards or distinctions on the part of the applicant is often encouraged, as is telling personal stories which humanize the applicant and make him or her more memorable. If the recommender has a personal connection with the organization or institution the applicant is applying to, it is appropriate to mention this as well.