Here's an explanation from their footer:
"Although Dewey invented his system in 1876, recent editions of his system are in copyright. LibraryThing's Melvil Decimal System is based on the classification work of libraries around the world, whose assignments are not copyrightable. The "schedules" (the words that describe the numbers) come from a pre-copyright edition of his system, John Mark Ockerbloom's Free Decimal System, and member contributions."
Can confirm that trains are an amazing place to meet people. I commute on the Amtrak Northeast Regional and have made 3 regular acquaintances with whom I've had long conversations.
Never would have happened on a plane or or on the highway.
* Remove Jelly browser with `adb shell pm uninstall --user 0 org.lineageos.jelly`
* Disable F-Droid so you can't install another browser on a whim with `adb shell pm disable-user org.fdroid.fdroid`