You have created a fully functioning location based alerting via the room management in combination with the alarm circle management. But the recipients should also be able to identify the person which has sent out the alarm. This is realized via the display name management.
This step is optional if your display names are clearly identifiable already.
In order to manage the display names please navigate to the respective menu.
Here you can find a list of every assigned display name.
You can create new relations via the button 
enter NT-Login to displayname assignment.
First please enter the login name (NT-Login) of the user and afterwards the display name which will be shown in the alarm text. The assigned name will immediately be taken over into the alarm configuration after saving.
Import a user list from the Active Directory
If you have names assigned in your Active Directory already, you can import them via the button LDAP import.
Every username of your directory service will be read.
The Active Directory which will be used for the import needs to be registered in the app Domains. You can enter as many domains as you want.
After choosing a domain you can now select which attribute you want to use as the display name. Then the domain can be searched through for this attribute. The results will then be shown in the table below.
Afterwards you can choose which assignment you want to import into the list. With the button Add marked entries to the list you can import the selected items to the list of display names.