DTLow thanks for the reply. I'd rather have custom on-the-fly tags and not need them then need them an not have them (current pain).
using tags is a "nodal" system of organization. if you need to work many sources, tags are far more important, especially for recalling "connected" sources later. on iOS not being able to "on-the-fly" create tags is an efficiency crime. Given the usage case above (owls), I would "on-the-fly" tag the "source" trails - owl's food - camping maybe even ornithology, just having the option means how information relates does not depend what my memory allows....
NO SQL my brain. Not everything is relational to what is in a "list".
Additionally if "on-the-fly" tags are not important, why do we have this feature in the desktop app? What happens when you find a "plumbing fixture" that is super modern for your "best" re-modeling customer? Do you file this twice in your hierarchy of "plumbing" and.... later create the new tag "offer to bob builder" then your realize modern fixtures is a good tag... sorry can't create this on-the-fly -- if it doesn't fit the list... re-organize while pounding salt iOS users