There are a frightening number of systems that don't allow "-", which isn't even an edge case. A lot of people - mostly women - hyphenate their last names on marriage, rather than throw their old name away. My wife did. She legally changed her name when she came of age, and when we met and married years later she said, "I paid for money for my name; I'm not letting it go." (Note: I wasn't pressuring her to take my name.) So she hyphenated it, and has come to regret the decision. She says she should have switched, or not, but the hyphen causes problems everywhere. It's not a legal character in a lot of systems, including some government systems.
Well, and remember: If in doubt, send them an e-mail. You probably want to do that anyways to ensure they have access to that mailbox.
You can try to use a regex as a basic sanity check, so they've not accidentally typed a completely different info into there, but the e-mail standard allows so many wild mail addresses, that your basic sanity check might as well be whether they've typed an @ into there.
Yeah, I'm just saying that the benefit of using such a regex isn't massive (unless you're building a service which can't send a mail).
a@b is a syntactically correct e-mail address. Most combinations of letters, an @-symbol and more letters will be syntactically correct, which is what most typos will look like. The regex will only catch fringe cases, such as a user accidentally hitting the spacebar.
And then, personally, I don't feel like it's worth pulling in one of those massive regexes (+ possibly a regex library) for most use-cases.
And you'd think a simple solution is just leave out the hyphen when you put you name in, but that can also lead to problems when the system is looking for a 100% perfect match.
And good luck if they need to scan the barcode on your ID.
Then the first part is interpreted (in the US, anyway) as a middle name, not as part of the last name. I did run into a recently married woman who did that: dropped her middle name, moved her last to the middle, and used her spouse's last name.
More commonly, places that don't take hyphens tend to just run the two names together: Axel-Smith becomes AxelSmith.
As someone who's mexican I encounter that more than one would think since I have 2 last names and it gets weird sometimes since I also have a middle name.
Something that could happen in Mexico for a name is Juan Maria as a first, Guillermo David as a middle and Gonzales De Mercado as a last name. Technically 7 words and totally a thing but not common at all, anymore at least.
I have come across a shockingly large amount of people who not only have a hyphenated last name but also have a hypenated first name! Dealing with every new computer system is like a new adventure