What limits are set in Plesk for username/password?

[mahesh]

Question
What limits are there in Plesk for username/password?

Answer
Usernames and passwords in Plesk are case-sensitive.

Username and password length have the following limits:

• Plesk user name length: from 1 to 255 symbols;
• Plesk user password length: from 5 to 255 symbols;
• System user name length: from 1 to 32 symbols for Linux, 1 to 20 symbols for Windows;
• System user password length: from 5 to 255 symbols;
• Mail address: up to 64 symbols (not counting '@' and domain part)

Character limitations are separate for different groups of users:

For Customers/Resellers:

• The first character is limited to alphanumeric characters.
• " " (Space) is prohibited.
• System user names on the OS (Linux "root" and Windows "Administrator") are also prohibited.

For additional users (added in Users > User accounts menu):

• The first character is limited to alphanumeric characters.
• Characters from all languages ��are allowed.
• Special sentences other than (& @.'+ -) are prohibited.
• System user names on the OS (Linux "root" and Windows "Administrator") are also prohibited.

Character limitations for system users are based on the target OS:

• For Linux, only lowercase English letters, numbers,-(dash), and .(dot) are allowed. The first character is limited to letters.
• For Windows, only English letters, numbers, -(dash), .(dot), _ (underscore) are allowed. The first character is limited to alphanumeric symbols.

Character restrictions for passwords:

• The string is limited to the first 126 ASCII characters.
• " " (Space), " " (quotation marks), "" "" (double quotation marks) are prohibited.
• The password cannot include the user name.
• Example: User: qwerty Password: 1@qwerty2$

The system user password restrictions are the same as the target OS, although they differ depending on the distribution.

These limits are hard-coded, which means they cannot be changed in Plesk configuration. Additionally, system limits have a higher priority than limits configured in Plesk.