From chapter 2 of Sharing Publication-Related Data and Materials: Responsibilities of Authorship in the Life Sciences, a publication of the National Research Council of the National Academy of Sciences, U. S. A., in 2003.
Community standards for sharing publication-related data and materials should flow from the general principle that the publication of scientific information is intended to move science forward. More specifically, the act of publishing is a quid pro quo in which authors receive credit and acknowledgment in exchange for disclosure of their scientific findings. An author’s obligation is not only to release data and materials to enable others to verify or replicate published findings (as journals already implicitly or explicitly require) but also to provide them in a form on which other scientists can build with further research. All members of the scientific community—whether working in academia, government, or a commercial enterprise—have equal responsibility for upholding community standards as participants in the publication system, and all should be equally able to derive benefits from it.
The entire book, reporting on the NRC “Committee on Responsibilities of Authorship in the Biological Sciences” in 2002, is available online for free.