diff --git a/infrastructure-guide/infrastructure_systems.md b/infrastructure-guide/infrastructure_systems.md
index f8be0d2c..07f67006 100644
--- a/infrastructure-guide/infrastructure_systems.md
+++ b/infrastructure-guide/infrastructure_systems.md
@@ -121,4 +121,10 @@ Access VM infrastructure for linux core employees:
 | ---- | ---- |
 | VC_Admins_Linux  | Access to the PSI VM Infrastructure |
 
+# AD Users
+| Group | Notes |
+| ---- | ---- |
+| lx-netops-api  | (keytab) Used to access the netops api |
+| lx_ad_join  | (keytab) Used to join a machine to AD |
+| linux_ldap ???? | was registered by Derek (he is noted as responsible in AD) - used for ???? |