Usernames and White Spaces

Question

In recent years, I have registered with various applications and platforms hosted online or offline.

Why white spaces are not allowed in User Names, since spaces are very natural for names, and most computing systems can handle them efficiently.

(Many people may raise similar questions about other special characters that are illegal, but their case is much more understandable, since they are not even natural for real-world naming schemes. And, of course ,!)

Answer 1

One subtle issue with spaces in user names is that the whitespace is “invisible,” and two adjacent spaces can look very similar to one space. Errors arising from entering two instead of one space can be difficult to distinguish, and this is one of the reasons to prohibit all spaces.

Some systems may prohibit spaces, but still allow inextricable space. A smart user can use this fact to include a space in their username.

Answer 2

, - - , , , Windows . , , C, , C .

, , , , , .

Answer 3

, , , , , .

, , , , "PWD".

Answer 4

, , , , . , . , fogbugz ( ) , , .

, - , , . - .:)

Answer 5

, , : , .

: , , , , (* nix ..).

Answer 6

, . " " "". , .

Answer 7

, . unix , unix - . , unix , .

, -, .

-, @ . - , , , , , , .