as far as Docs are concerned, Amazon is not thinking clearly here and are using terms in a confusing manner. I doubt they are purposely trying to mislead us, but they need to consider the confusion level of what they are saying.

Amazon is loosely using Personal Documents in a confusing manner which can result in us thinking that they are referring to the Personal Documents that can be archived and synced via the Kindle Personal Documents Service. There are two definitions for Personal Documents as used by Amazon:

• A non-Amazon Store document that was sideloaded or emailed to your Kindle.
  • Document cannot be archived
  • Document cannot be synced with other Kindles
• A non-Amazon Store document that you emailed to your qualifying K3 or K4 to take advantage of the Kindle Personal Documents Service for purposes of archiving and syncing with other qualifying Kindles.
  • Document can be archived
  • Document can be easily downloaded from Archive to qualifying Kindles
  • Document can be fully synced with other qualifying Kindles

I wish they would use the terms sideloaded document for non-archiveable non-syncable docs and personal document for archiveable and syncable docs. They are not the same at all. I'm disappointed that the Fire and K4PC don't qualify to work with the Kindle Personal Documents Service. I hope Amazon adds them soon, but I'm not holding my breath.