Ok, I don’t get it. I can send a PDF to all my Kindle devices (both Kindle readers and iPads running the Kindle app) using the “Send To Kindle” app from my Windows PC, and it has the option to “archive document in your kindle library” as this pic screenshot shows:
If I do this more than once with the exact same PDF, I get duplicate pdfs available on all my devices (even the ones that I didn’t click the check box to deliver them to when I did the Send To Kindle action.
Thanks. That "digital-console/contentlist’ link you gave does indeed show all my PDFs if I click the “docs” option. That’s a big relief and does indicate that my PDFs are stored safe and sound in my Kindle library in Amazon’s great big bag of storage in the “cloud”. I now wonder if there is a limit to how much space I am allowed take up? Is there a limit? 5 GB, 10 GB, etc., or would I eventually have to pay for the privilege if I go over the free limit?