Update regional-availability-include.md

Author: krkutser

articles/communication-services/includes/regional-availability-include.md

@@ -8,4 +8,4 @@ ms.custom: references_regions
 
 ---
 > [!IMPORTANT]
-> SMS capabilities depend on the phone number you use and the country/region that you're operating within as determined by your Azure billing address. For more information, visit the [Subscription eligibility](../concepts/numbers/sub-eligibility-number-capability.md) documentation.
+> SMS and PSTN capabilities depend on the phone number you use and the country/region that you're operating within as determined by your Azure billing address. For more information, visit the [Subscription eligibility](../concepts/numbers/sub-eligibility-number-capability.md) documentation.