The title is pretty self-explanatory.

All the letters of the (English) alphabet, all numbers, the underscore (_) and the hyphen (-).

Basically what @WindOctahedron said. Also, no special binary characters, no special text, just stuff you find on your normal qwerty keyboard.


Though I think if you use something like a Russian Keyboard's letters, they still work.
*or any other languages letters

If an exhaustive list is what you're looking for, the characters below are the ones you can use in usernames:

ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_

Spaces aren't allowed.

Capital letters are allowed.

Thanks for your above comments.

I just have another point:
Which is better with respect to your point of view?
Suppose we have two-parted names: First and Last
What would be better recommended as a user name:
1. FirstLast
or
2. First-Last

?
I tried an empirical situation of projects exploration, typed both cases that I really need your feedback.
Thank you in advance.

GamalZayed wrote:

(#7)
Thanks for your above comments.

I just have another point:
Which is better with respect to your point of view?
Suppose we have two-parted names: First and Last
What would be better recommended as a user name:
1. FirstLast
or
2. First-Last

?
I tried an empirical situation of projects exploration, typed both cases that I really need your feedback.
Thank you in advance.

It depends on the user's opinion (And, if they code other languages, which one they use). Any of the following might be done:

Firstlast
firstLast
FirstLast
First-Last
First_Last
-First_Last-
xXFirstxLastXx

and almost infinite variations thereof.

Btw asking ST to close because this was a necropost.
Please don't necropost.