There is a need to be quite clear about which ACTIONs can be used for a given INSTRUCTION.
To Archetype this we need to state this relationship in the INSTRUCTION. As ACTIONs are
likely to grow in number and be quite diverse - whereas INSTRUCTIONs may be much more
limited in number and take their activity.description(s) from one or more action archetypes.
It seems sensible then to archetype the relationship from the INSTRUCTION.