John Gruber16 years in and iOS still doesn't have this feature that MacOS (née Mac OS X) has had since it launched 22 years ago: “Learn Spelling”.
David Nelson@gruber You may already know, but you can go to Settings > General > Keyboard > Text Replacement, and add a word with no shortcut. This will stop the OS trying to replace it, and will keep it from getting underlined. Absolutely not ideal, but it’s an escape hatch for those chronic problem words.
@dmnelson I do know that but it’s a terrible solution to this problem.