If that restriction on a free text field is due to an overly restrictive firewall then you are still shifting your problem to the user instead of fixing the issue. "Our firewall will block some nonalhanumeric text so you cannot enter you company's name if it contains a colon." is just the same als "We can't or won't implement our inputs to not cause problems so you cannot enter you company's name if it contains a colon." The result of both would be that a company named Do:!T could enter it's proper name into your system except in ways like DocolonexclamationmarkT. This does not look nice and will continue to not look nice wherever that company name pops up down the line. There can be reasons for not fixing something. If you operate in the US you may not be interested in spending effort on implementing Cyrillic input. But if you do operate in the US then colons and exclamationmarks are a normal part of the characterset.

Yes: https://opensea.io/assets/0x92...