Uh, apparently the author didn't notice that on a couple platforms, you can generally type into a select box and it will act sorta like an autocomplete. I do this all the time for US state select boxes, I tab into them and press 'T', 'T' which generally gives me 'TX' which follows 'TN'. Select boxes are for long exclusive lists. I would like to see all the US states in a radio grouping... Not..
(As a web developer, I of course totally understand that sometimes you need to ensure the input is the 2-letter code and not the full word or not mis-spelled... but it's not like zip code are dropdowns, and those are often more important than the state in terms of matching up to an existing record in some database somewhere.)