Update route-maps-about.md

adding customers should not remove BGP communities.

Author: cfields475

articles/virtual-wan/route-maps-about.md

@@ -58,6 +58,8 @@ Before using Route-maps, take into consideration the following limitations:
 * When adding ASNs to the AS-PAT, only use the Private ASN range 64512 - 65535, but don't use ASN's Reseverd by Azure:
   * Public ASNs: 8074, 8075, 12076
   * Private ASNs: 65515, 65517, 65518, 65519, 65520
+* When using Route-maps, please do not remove the Azure BGP communities:
+  *  65517:12001 , 65517:12002 , 65517:12003 , 65517:12005 , 65517:12006 , 65518:65518 , 65517:65517 , 65517:12076 , 65518:12076 , 65515:10000 , 65515:20000
 * You can't apply Route-maps to connections between on-premises and SD-WAN/Firewall NVAs in the virtual hub. These connections aren't supported during Preview. You can still apply route-maps to other supported connections when an NVA in the virtual hub is deployed. This doesn't apply to the Azure Firewall, as the routing for Azure Firewall is provided through Virtual WAN [routing intent features](how-to-routing-policies.md).
 * Route-maps supports only 2-byte ASN numbers.
 * The point-to-site (P2S) Multipool feature isn't currently supported with Route-maps.