service (type) heading

The heading of service diagrams is:

<service-heading> ::= service [<qualifier>] <service-name>

while service type diagrams have the following heading:

<service-type-heading>::=
[< virtuality >]
service type [< qualifier >] <service-type-name>
[<formal-context-parameters>]
[< virtuality-constraint >][< specialisation >]