why "name" more than word characters plus maybe . - and ' ?

I hope the space between '.' and '-' is significant: it is thankfully rarer these days, but I've lost count of the number of times I was rejected by a web form because "van der Sanden" did not match their concept of a valid surname. In the majority of cases, those websites lost the chance at my custom.

Finding the right balance between strict and permissive can be hard. My preference is to look for unmistakable signals of intentional manipulation - and then ideally blackhole the IP address without further ado - but to accept anything below that high threshold, and concentrate on doing the right thing with it thereafter.