Anything you didn't work on.Rule of thumb: If you didn't actually create anything original or play an integral role in the campaign then don't put it in your book.
Your portfolio is a representation of you and your skills. Putting something that you didn't come up with, write or design in your book is not only lying but it's also stealing.
Christopher Columbus got in a boat, landed (accidentally) on some islands where there were already people living there, put down and flag and said he discovered said place, and went on to name it. How do you "discover" something that people already know about?
And how are you going to do some resizes or edit some body copy and decide that this is your campaign?
Don't Columbus people's work. It's stealing and it's ugly.
As an intern/freelancer/junior you will probably be working on a lot of other people's stuff. That doesn't mean you can put the whole campaign in your book. It's not yours.
If you created a small piece of an overall campaign, only show that small piece. But don't put in the full thing as if you were at all the brainstorm sessions, working out the intricacies, pitching to the client or staying up late getting the assets ready for hand off.
Just because your mouse touched it or you were in a meeting or two, doesn't make it yours. There were already people on that land - um, I mean campaign - you cannot claim it.
Recruiters and creative directors are going to assume the work in your book is yours. Some will ask hows or whys and it's gonna be hard to answer those questions if you didn't actually play an integral role on that stuff. If you get hired, they'll expect you to do similar work and if you can't... *cue menacing music*
Feel free to list it on your resume as clients you worked on, but if you can't explicitly say "I came up with this" or "I wrote that" then don't put it in.
Plus, don't be an asshole. Or Columbus.
