Hi. I wold also read [1][2]. I have also given talks at ApacheCon on this, see [3][4] for examples. Both [3] and I think [4] predate the work in progress disclaimer, which makes it easier for you.
Thanks, Justin 1. https://www.apache.org/legal/resolved.html 2. http://www.apache.org/dev/licensing-howto.html 3. https://www.youtube.com/watch?v=I0-lp1t9ee0 4. http://training.apache.org/topics/ApacheWay/NavigatingASFIncubator/index.html