Last half year I spent on migrating our clients from Dynamics CRM 2011 to 2015 version. That was a long and interesting journey. In some periods it was really exhausting... Trying to manage with all the issues that come up from CRM bugs and behavior nuances to our product specific

In Dynamics CRM on-premise deployment PrinicipalObjectAccess (POA) table contains implicit and explicit entity sharing. Explicit sharing can be created and checked directly with UI via Share button. Implicit sharing is created during different processes by CRM itself: account merging, emails with users in CC, workflows, etc. During active CRM usage