I stumbled on a list of rarely used HTML attributes today. Two stuck out:
enterkeyhintto swap the enter key on a form field from “Go” to “Next”, etc. I knew certain keyboard types, like email, could change the text on this field, but I didn’t know there were more options. You can’t just put in text willy-nilly, so do check out the docs on the options.
formon form fields allows a field to be placed outside of a
<form>tag. I haven’t needed this often, but when I have, it was always a pain.
The others are less useful, but still good to know about.