The requirements for anonymous user usernames in the document do not match the actual situation.

[xavierskip]

in the document

• the name has to start from the letter and contains letters, numbers, underscores and spaces only**

but in fact, you can use "456" as the anonymous username. so how is the name has to start from the letter?

you can see the user "456"'s comment in https://remark42.com/demo/