What are the different validations for creating Users in Appian?

1. The username should be unique
2. The first and last names should be present.
3. If this is a multi-tenant application, you might also want to apply security on the users.
4. You can always apply a character limit to everything. 

Hi,

FYR https://docs.appian.com/suite/help/23.3/User_Management.html#create-a-new-user and there is a default character limitation in Appian 

Username- 255 ASCII letters

First Name, Last Name and Nick Name field - 35

Email - 72