https://learn.microsoft.com/en-us/dotnet/api/system.reflection.emit.opcodes.initobj?view=netframework-4.8.1&viewFallbackFrom=net-10.0&redirectedfrom=MSDN
OpCodes.Initobj Field (System.Reflection.Emit) | Microsoft Learn
Initializes each field of the value type at a specified address to a null reference or a 0 of the appropriate primitive type.
field systemopcodesreflectionemitmicrosoft