Anybody know what these IRP flags are?

In my volume filter I’m seeing Irp->Flags for write IRPs set to either
0x60043 or 0x60201. I can’t find anything in the header files that
matches the 0x40000 or 0x20000 bits. Does anyone know what these are?
I need to construct some raw volume write IRPs so I was looking at
system generated IRPs as a template of what bits need to be set. But
I don’t want to just blindly copy the 0x60000 without knowing what it
is.

-JT