Hi Pietro,

Product version is IRIS 2023.1 does not have an arrayref() reference creation function built in. 

It is likely you are viewing a more recent version of IRIS documentation which does include arrayref(). This documentation InterSystems IRIS Python Module Core API is specific to your version of 2023.1 and lists the available reference creation functions of cls()gref()ref(). This is why the example code using arrayref() is not working for you. One option is to upgrade to IRIS 2023.2 which does include arrayref().

The list type of Organizations existed prior to the changes I am making and is in use within the application in other places. As such I was ideally hoping implement the cascade deletion without changing that type. However, a Parent/Child relationship as both you and @Iryna Mykhailova suggested is a great option for the automatic cascade deletion and I will definitely consider the benefits of that change. Thank you!

Thank you for the clarification. For the given situation, there would never exist multiple lists that hold the same organization object. Following your example, my tables would be as such. 

Organization
ID
1
2
3
4
5
GetOrgUpdatesResponse
ID Organizations
1 2
2 1,3
3 4,5

So that there would not exist a situation where a deletion of a list in GetOrgUpdatesResponse would result in any other list containing incorrect data.