Hyphens and check symbols are also valid in Crockford’s base 32.

Nobody has claimed this yet.

> Hyphens (`-`) can be inserted into symbol strings. This can partition a string into manageable pieces, improving readability by helping to prevent confusion. Hyphens are ignored during decoding. An application may look for hyphens to assure symbol string correctness.
>
> — https://www.crockford.com/base32.html

> An application may append a check symbol to a symbol string. This check symbol can be used to detect wrong-symbol and transposed-symbol errors. This allows for detecting transmission and entry errors early and inexpensively.
>
> The check symbol encodes the number modulo 37, 37 being the least prime number greater than 32. We introduce 5 additional symbols that are used only for encoding or decoding the check symbol.
>
> The additional symbols were selected to not be confused with punctuation or with URL formatting.
>
> `0123456789ABCDEFGHJKMNPQRSTVWXYZ` `*~$=U`
>
> — https://www.crockford.com/base32.html

Have it ignore `-`, `*`, `~`, `$`, `=`, `U`, and `u` in your inputs.

Start at the package's JavaScript decoder entry point and review how input symbols are handled. Verify that hyphens and the listed check-symbol characters are handled as requested, including both uppercase and lowercase U, with tests covering these inputs.

Written by the indexing model from the issue text.