In science, intellectual contribution to a project is sufficient for someone to be the author of a document. When writing software documentation, this would imply that almost everyone involved in the software development would be included as co-authors.
Unlike in science, it seems odd to include the names of people who do not actually work on the document. One reason is that documentation is constantly evolving and I am concerned about making sure that co-authors regularly review the current state of the document.
question: When writing documentation, are there guidelines for whom, other than those who directly contribute to the document, should be considered an author?
clarification: I am writing documentation about how to use an open source software and database built by and for scientists. As this project represents most of our the team's cumulative experience with software development, we have no existing policies for authorship of documentation (unlike we do with journal articles).