Don't know which video(s) either, but it's mainly related to multiple Split Databases. When the applicable tables are connected in 1 database, it will work and you can use it, but when the applicable tables are in different databases, Referential Integrity doesn't work.

Richard Garber and Daniel de Koning
Richard said:
1) Referential Integrity does not work if you have multiple backend tables. It will work if you have single backend table.
2) He likes to take care of cascading delete in code. This way he can control what happens and it will always work.
3) If you do it in code, you can Control the process and warn the user if needed.

Okay, thanks! Just wondering. Begging my pardon on this I mean to include a question mark in my OP title "You don't use RI?" I got that from this video "How to Delete the Sample Records From Your Microsoft Access Database Before Release" and it's something very briefly said around the three minute mark. I was just asking from a beginner's perspective why. I used Access way back in the mid 90's for writing databases for local businesses. Self taught too. But I've forgotten about 99% of what I did and Access looks a bit different from the Access 95 days. It was noted back then that Access wasn't a great performer over networks and, well, we didn't even look into that. I moved onto using Clarion (TopSpeed) and I don't even think I had the next version of Access. I did like it though. Clarion was a lot like Access though it was a compiler converting the interface and code (written in C++) to an EXE.

I run Access Frontend on 45+ computers scattered across the state, and my backend sits in 2 files located at one facility.
Runs fast and with no issues even during heavy traffic times.

Sami hit the nail on the head. I use RI very sparingly.