I’m a reporter for the Events and Styles section for my newspaper. Last week I was at a music awards event, where I saw one of the posters advertising the event had a hilarious typo in it. I want to run that poster with a blooper caption in the paper. Do I have to ask the publicist for the music awards for permission? I want to use the whole poster; otherwise, it won't make sense.
Thank you for your question. Fair use is, of course, a case-by-case situation, but many situations are very similar to each other in the workplace. Fortunately, you can benefit from the consensus view of your community on these common situations. In this case, you can consult the Set of Principles in Fair Use for Journalism  to get help with your reasoning. The second situation can help you: “Fair use applies when journalists use copyrighted material as documentation, to validate, prove, support, or document a proposition.”
You can see if you have stayed within the limits of fair use by asking yourself if you used the appropriate amount to make your point. In this case you say the whole thing is what is appropriate, and that sometimes is the case. Courts have said you can use the whole thing when you need to do so for the new and transformative use. Is this true in your situation? You'd also ask, is this evidence valuable to viewers in believing or understanding your claim? Is the attribution clear? As you can see, the nature of the caption will be important to your decision.
Once you have answered these questions, you’ll be able to figure out whether using the poster constitutes fair use in conformity with the consensus of the profession, and you can make your fair use call with confidence.