Is it cruel to brand a seal?
Dear Rich: I have a question. If all works created by the U.S. government are in the public domain, can I reproduce the Copyright Office seal at my website? I'm so glad you asked because I was just looking at the 'rebranded' (.pdf) Copyright Office seal and wondering, what was wrong with the old one? (Branding is so dumb ... even sheep hate it.) You can freely reproduce the Copyright Office seal with one exception; you can't use it in any way that indicates you are associated with or endorsed by the Copyright Office. That's because the seal is a registered trademark (Serial No. 89000946). That's right, federal agencies can own trademarks (and the trademark serial numbers always start with 89).
For more about reproducing works that are in the public domain, see The Public Domain: How to Find Copyright-Free Writings, Music, Art & More, by Attorney Stephen Fishman (Nolo).

