Configuring Permission Sets Using the .NET Framework Configuration Tool (Mscorcfg.msc)
Each security policy level has a set of permission sets that can be associated with code groups on that level. You can create a permission set for a particular level and associate it with a new or existing code group.
You can use the .NET Framework Configuration tool (Mscorcfg.msc) to configure permission sets.
The .NET Framework includes several built-in permission sets. The only built-in permission set that can be changed is the Everything permission set.