Lee suggested to not use +

Author: benjie

spec/Appendix C -- Grammar Summary.md

@@ -425,7 +425,7 @@ ServiceDefinition : Description? service Directives? { ServiceCapability* }
 
 ServiceExtension :
 
-- extend service Directives? { ServiceCapability+ }
+- extend service Directives? { ServiceCapability* }
 - extend service Directives [lookahead != `{`]
 
 ServiceCapability :

spec/Section 3 -- Type System.md

@@ -2423,7 +2423,7 @@ This version of the specification defines the following capabilities:
 
 ServiceExtension :
 
-- extend service Directives? { ServiceCapability+ }
+- extend service Directives? { ServiceCapability* }
 - extend service Directives [lookahead != `{`]
 
 Service extensions are used to represent a service which has been extended from