add must-keep collection

windows/security/operating-system-security/network-security/windows-firewall/assign-security-group-filters-to-the-gpo.md

@@ -5,6 +5,7 @@ ms.prod: windows-client
 ms.collection: 
   - highpri
   - tier3
+  - must-keep
 ms.topic: conceptual
 ms.date: 09/07/2021
 ---

windows/security/operating-system-security/network-security/windows-firewall/best-practices-configuring.md

@@ -6,6 +6,7 @@ ms.date: 11/09/2022
 ms.collection: 
   - highpri
   - tier3
+  - must-keep
 ms.topic: best-practice
 ---
 

windows/security/operating-system-security/network-security/windows-firewall/create-a-group-policy-object.md

@@ -5,6 +5,7 @@ ms.prod: windows-client
 ms.collection: 
   - highpri
   - tier3
+  - must-keep
 ms.topic: conceptual
 ms.date: 09/07/2021
 ---

windows/security/operating-system-security/network-security/windows-firewall/create-an-inbound-port-rule.md

@@ -5,6 +5,7 @@ ms.prod: windows-client
 ms.collection: 
   - highpri
   - tier3
+  - must-keep
 ms.topic: conceptual
 ms.date: 09/07/2021
 ---

windows/security/operating-system-security/network-security/windows-firewall/create-wmi-filters-for-the-gpo.md

@@ -5,6 +5,7 @@ ms.prod: windows-client
 ms.collection: 
   - highpri
   - tier3
+  - must-keep
 ms.topic: conceptual
 ms.date: 09/07/2021
 ---

windows/security/operating-system-security/network-security/windows-firewall/open-the-group-policy-management-console-to-windows-firewall-with-advanced-security.md

@@ -5,6 +5,7 @@ ms.prod: windows-client
 ms.collection: 
   - highpri
   - tier3
+  - must-keep
 ms.topic: conceptual
 ms.date: 09/08/2021
 ---

windows/security/operating-system-security/network-security/windows-firewall/windows-firewall-with-advanced-security.md

@@ -5,6 +5,7 @@ ms.prod: windows-client
 ms.collection: 
   - highpri
   - tier3
+  - must-keep
 ms.topic: conceptual
 ms.date: 09/08/2021
 ---