If you would like to use some copyrighted material (part of an article, photo, webpage, etc.) in something that you are working on, you can ask permission from the copyright holder. To do this, you first need to find the copyright holder. Hopefully, this can be easily accomplished by getting in touch with their workplace and/or publisher.
However, if you are not able to ascertain where they work or who they work for, you will need to look further. Some other things to try to locate the copyright holder:
These websites have good overviews of the process involved in getting permission to use a copyrighted work:
The Basics of Getting Permission.
Stanford University Copyright and Fair Use
Getting Permission to Use the Work of Others.
Citizen Media Law Project
Sample letters requesting permission to copy.
An orphan work is a work that is protected by copyright but for which the copyright holder is not known or, if known, not able to be located. As a result, it is impossible to ask permission to use part or all of the work.
The problem of orphan works has been growing due to a number of reasons:
Although there is some discussion in copyright circles that the search for "orphan works" should be simplified or eased, at this point someone who wants to request permission to use a work must do a search for the copyright holder.
There has been proposed legislation to fix the orphan works problem but, currently, nothing has been passed. There have also been proposals from groups outside the Congress, such as the Center for the Study of the Public Domain. The group "Public Knowledge" also has a position on orphan works.