Hydraulic Piston Ring Order of Installation

Is there is a preferred order of installation (T – M – B, B – M – T) for hydraulic piston rings?  July 3, 2016.

Sometimes the marks on the rings look like a pit or flaw in the surface, and sometimes like a drill mark. As for the order of installation, it doesn’t matter. As for the mushrooming, I’m not sure. Is it possible the top of the piston was hitting the end of the cylinder? Interestingly they used to advocate washing engine cylinder walls with soap and water to prevent solvents from pushing grit into the pores. That’s not a big concern with hydraulic lift cylinders however.