Documentation is intellectual property that may be included in downstream products just as easily as actual code, so steps need to be take to mitigate the risks associated with that adoption.
The Eclipse IP Due Diligence Process primarily a matter of intellectual property risk mitigation. The Eclipse IP Policy understands risk in intellectual property and exists to do that work on behalf of our project teams. While I appreciate that you don't want to overwhelm them with additional work, the fact remains that leveraging their expertise in intellectual property management is a critical part of the process.
So... you really need to follow the IP Policy and process regardless of how the documentation is actually represented. Are you expecting many significant contributions (e.g. more than 1000 lines)? I suspect that for most contributions, you'll just need to track the contribution and not necessarily engage the IP Team.
FWIW, it's true that the use of the Eclipsepedia Wiki for documentation represents a bit of a grey area. Contributions there are covered by the website terms of use. Strictly speaking, however, if a project harvests wiki-based information to produce official documentation, the IP Policy applies.
HTH,
Wayne
