Turnitin have produced a white paper which gives a list of 10 Types of Plagiarism. Primarily a US publication, it introduces its content thus:
“This white paper distills a study of thousands of plagiarized papers, providing examples of 10 distinct types of plagiarism that comprise the vast majority of unoriginal work in student papers. These types are defined across a spectrum of intent and have been given titles to reflect both the influence of the Web on plagiarism and to help make the definitions more meaningful to the generation of students who are “digital natives.””
You can download the paper from the Turnitin User Group pages.