You can't use selective deployment with wildcard service chaining. He…

…re's why

Signed-off-by: itowlson <ivan.towlson@fermyon.com>

content/spin/v3/http-outbound.md

@@ -218,12 +218,14 @@ You must still grant permission by including the relevant `spin.internal` hosts
 allowed_outbound_hosts = ["http://authz.spin.internal", "https://reporting.spin.internal"]
 ```
 
-To allow local chaining to _any_ component in your application, use a subdomain wildcard:
+To allow local chaining to _any_ component in your application, you can use a subdomain wildcard:
 
 ```toml
 allowed_outbound_hosts = ["http://*.spin.internal"]
 ```
 
+However, the wildcard implies that the component requires _all other_ components to be local to it. You will therefore not be able to use [selective deployment](./running-apps#splitting-an-application-across-environments) for an application that uses wildcard service chaining.
+
 > Local service chaining is not currently supported on Fermyon Cloud.
 
 ### Intra-Application HTTP Requests by Route

content/spin/v3/running-apps.md

@@ -188,7 +188,7 @@ $ spin up -f registry.example.com/app:1.1.0 -c chat-engine -c sentiment-analyzer
 
 > In practice you'd set these commands up in a scheduler or orchestrator rather than typing them interactively - or, more likely, use a selection-aware scheduler such as [SpinKube](https://www.spinkube.dev/) rather than running `spin up` directly.
 
-If you run a subset which includes a component that uses [local service chaining](./http-outbound#local-service-chaining), then you must also include all chaining targets in the subset - Spin checks this at load time.  [Self-requests](./http-outbound#making-http-requests-within-an-application) will work only if the target route maps to a component in the subset, but this is not checked at load time - instead, self-requests to unselected components will fail at request time with 404 Not Found.
+If you run a subset which includes a component that uses [local service chaining](./http-outbound#local-service-chaining), then you must also include all chaining targets in the subset - Spin checks this at load time. (Wildcard service chaining - the `*.spin.internal` host - means that _all_ components are potential chaining targets, so you will not be able to use selective deployment if any component uses wildcard service chaining.) [Self-requests](./http-outbound#making-http-requests-within-an-application) will work only if the target route maps to a component in the subset, but this is not checked at load time - instead, self-requests to unselected components will fail at request time with 404 Not Found.
 
 ## The Always Build Option