Named Credentials allows to store per user credentials, which can be referenced by common name.

User's personal instance of Named Credentials is called Personal Named Credentials

Personal Named Credentials name always starts with @ symbol

Example

You have several employees who support customer's Contoso Corp. infrastructure.
Each of your employees has a user in Contoso Corp. Active Directory.

You create a Named Credentials object @contoso.corp and each of your employees can create a Personal Named Credential referencing this Named Credentials object.

This allows connections without requiring password but with different password for every user.

If a user doesn't have a Personal Named Credential required for this connection he will be asked for login in those cases: - SSH connection - RDP connection with RDP security

User will not be able to connect if RDP connection uses NLA or TLS security, because this connection requires username/password to start network connection and will not show login screen for unauthenticated users.