Easy, 36-base slider with 6 place holders. All potential post codes between 000000 and ZZZZZZ.

If you’re using the book correctly, you couldn’t say the same thing. Using a flora book to identify a plant requires learning about morphology and by having that alone you’re already significantly closer to accurately identifying most things. If a dichotomous key tells you that the terminating leaflet is sessile vs. not sessile, and you’re actually looking at that on the physical plant, your quality of observation is so much better than just photographing a plant and throwing it up on inaturalist