I don't believe there is anything wrong with specifying at a high level, what is happening in your context diagram. Afterall, it would be pretty useless labeled, User, System and Hospital staff. The context diagram is a tool to help us in the design of the system is it not?
Wikipedia suggests that we may provide abstract detail. ".....The relationships are labeled with a subject-verb-object format. For example, "customer places order."...... " - http://en.wikipedia.org/wiki/Context_diagram
Wikipedia suggests that we may provide abstract detail. ".....The relationships are labeled with a subject-verb-object format. For example, "customer places order."...... " - http://en.wikipedia.org/wiki/Context_diagram