The displayed DT of devices can be displayed with a prefix, e.g. -M1, or without a prefix e.g. M1. You can make this setting separately for all device groups. Device groups are (e.g.) "General devices", "Terminal strips", "Plugs", "Black boxes".

Precondition:

You have opened a project.

1. Options > Settings > Projects > "Project name" > Devices > DT
2. In the Settings: DT dialog, in the Set preceding sign group box, select the check box of the device group whose displayed DT is to be shown with a prefix.
3. Click [OK].

See also

Specifying Online Numbering Format

Automatically Numbering New Devices

Excluding Device Groups from Automatic Numbering

Automatically Numbering Devices in Macros / Copies