We have all been victimized by not double checking our work, but when it is going into print for wide public circulation it is even more important. Check the details and spelling or you may end up with unfortunate result.
One of the classics in the development field was a southern California advertisement campaign for a religious organization that was launched in print, in direct mail letters and on television. Some one forgot to double check the phone number. When people called the number it went to a sex line. Two numbers got reversed.
Below is another recent advertisement. One letter difference significantly changes the meaning...or maybe it was a Freudian slip.