"+" symbol in search shows available, but not registerable (miss match)

Hi,

1) + Symbol not registerable:

During the process of buying BNSs, I have encountered many fail txs from:
- passing the search availability,
- passing the Pre-ordering,
- but failing at Registering.

- After asking around in Stacks Discord support, found the "+" symbol cannot be registered.
- Jasper.#0260 on Discord kindly pointed out + symbol doesn't work, and taught me how to check via https://explorer.stacks.co/sandbox/contract-call
and yeah the "+" returns "error 2022" while on the main webpage shows as available.

> Can someone confirms this, and let me know what other symbols are acceptable and unacceptable?
> Perhaps this warning can be added to the website?

2) Can't register more than 1 BNS per address warning sign:

Another issue is that people who just go on the website do not know u can only hold 1 per address, I was one of the person and pre-ordered 5 names... If this warning can be put somewhere clear near the search bar or during the process, will be great.

Thank you Hiro team!!!!!



Start by reproducing the mismatch through the website search, pre-order, and registration flow, then compare it with the contract-call result linked in the issue. Check how unsupported symbols and the one-name-per-address restriction are presented; done means the availability result no longer misleads users and both constraints are clearly warned about.

Written by the indexing model from the issue text.