A written character reference is a commitment on the part of the writer. You're going in writing, testifying to the good qualities of someone. In many cases, particularly employment or a position of trust, these letters are extremely important to the person for whom you're providing the reference.
The letter's content is defined by:
The purpose of a character reference is to provide an insight into the subject.
You may be giving a reference, but that reference has to mean something to a total stranger. Information content is the key.
Very important: When writing a character reference letter, you are really giving the reader an indication of the nature of the person. You can't just write This is a great person, and leave it at that, because the statement is meaningless without a context.
To do that, you must clarify your opinions, and put them in context with your character reference. You're actually explaining why you're prepared to give them a reference, which is based on your opinion and knowledge of the individual.
A very basic example is a character reference for employment purposes. This is the most common form of character reference, and it addresses all the issues of writing this sort of letter:
To Whom It May Concern:
I've known John Smith for 10 years, as a former supervisor and professional acquaintance at ABC Inc.
He is an extremely reliable, conscientious, productive and honest worker.
He's punctual and very quality conscious. I've found him to be meticulous in his accounts work, and an excellent team member, contributing useful inputs on a regular basis.
John is very much a self-starter, able to work without supervision because of his own high standards of performance. He checks routinely to ensure his work for the company and advice to clients is correct, ensuring good service at all levels. He has received a lot of praise from his co workers, as well as management, for his efforts to help them.
We were all very sorry when John had to leave the company for family reasons and return to his home state. He's a very welcome guest when he can get to one of our firm's social gatherings.
Anyone employing John will find they've hired not only a valuable person, but a particularly decent person in whom absolute trust can be placed.
This letter's content is dictated by the nature of the subject, but as you can see, his character is the main issue, put in context, explaining the basis of your opinion. You've also provided extra information which wouldn't be part of a normal job application.
The letter addresses:
When you've written your character reference: