That’s a good solution if the goal is arbitrary list decorations, but the HTML type attribute is specifically meant for semantically-meaningful situations where the difference between list markers are more than decorative. From <ol>: The Ordered List element - HTML: HyperText Markup Language | MDN
Unless the type of the list number matters (like legal or technical documents where items are referenced by their number/letter), use the CSS
list-style-typeproperty instead.
It’s a common enough need that although the HTML attribute was deprecated in HTML 4.01 (with justification of it being purely stylistic), it was subsequently re-introduced in HTML5 for the specific purpose of encoding reference lists as described by MDN.