At the moment, when we create properties to hold the FKs involved in an implicit many-to-many join entity, we define the names of those properties from "{ETSN}_{propName}" where {ETSN} = declaringEntityType.ShortName(), {propName} = the property's name on declaringEntityType, where declaringEntityType is in turn both of the two outer entities in the join and the properties are from that entity type's PK.

At the Design Meeting on July 8 we decided to update this to name the foreign properties whatever we use elsewhere in the code when creating FKs "behind the scenes".