1. Does giving full credit in the text substitute for permission? Not at all: The law says that copyright infringement is the "unauthorized use." To be authorized, you must have permission before using it, not thanks afterwards.

2. I plan to write an adaptation of a copyrighted work, do I need permission? Definitely: Adding a layer of copyrighted material (yours) to an original work does not negate that original work's copyright protection. This is especially important for screenwriters. An option on a previously published book or life story is essential before adapting it for the screen; otherwise, you could waste a lot of time. Agents and producers usually will not consider or commission a screen adaptation without a signed option agreement.

3. Do works in the public domain require permission? Sometimes: A work may still have legal protection once its copyright expires. The character of Sherlock Holmes is trademarked; ideas may be protected under contract law; information may constitute a trade secret; and human beings have the right to control how their likeness and name are used. Make sure the public domain work is not protected in any of those ways.

4. Should I wait to get permission until after the manuscript is done and I'm sure that the work is being used? Definitely not: A copyright owner is never obligated to give you permission, or may charge whatever he or she wishes. Your work could become hostage to copyright permission. You could miss a deadline. You could get chewed.

5. Do I need permission even if my work is for nonprofit, educational purposes? Yes: In deciding copyright infringement, courts focus on what harm has been done to the value of the copyrighted work, not your motives. Harm can be done by a not-for-profit publication as well as a for-profit one. Unless you are certain that your use falls under the "fair use" provision of copyright law, you should acquire permission. Be conservative: it's better to know than not know that an author disapproves of your use.

6. Do I need to get permission since the work I'm using is now out of print? Yes. Out-of-print does not mean out-of-copyright. Out-of-print could be a temporary condition.

7. Since I'm using only a small portion, am I covered under the "fair use" provision? Not necessarily: The courts have no mathematical formula for determining what is and isn't fair use. However, the courts have ruled, "you cannot escape liability by showing how much of [the] work you did not take." The prevailing issue is harm caused by your use, not the amount. Did your use cause commercial harm to the copyright holder? That's the bottom line.

8. The work I'm using is a U.S. government publication. Do I still need to get permission? No: US government publications are not copyrightable. However, you must provide a full and accurate citation using your publication's preferred style guide.

9. If the work doesn't contain a copyright notice, do I still need permission to use material from it? More than likely: For works created after 1978, statutory copyright automatically exists when the author first expresses his creation in "tangible form." Before 1978, works published without a copyright notice did indeed risk losing their protection. But not today.

10. Do anonymous works posted on the Internet require permission for use? Not likely but make sure: Copyright law specifically protects anonymous and pseudonymous works, but posting anonymously in hopes that others will share it is common on the Internet.

The need for copyright permission can be summarized thusly -- when in doubt, don't do without.