indemnify. 1  to compensate for damage or loss sustained, expense incurred, etc. 2  to guard or secure against anticipated loss; give security against (future damage or liability).
Counter-flashing (or cover flashing, cap flashing) is a term used when there are two parallel pieces of flashing employed together such as on a chimney, where the counter-flashing is built into the chimney and overlaps a replaceable piece of base flashing.
1 They are usually well-sealed, but corrosion of the pipe flashing or of the sealant can allow water to seep through to the interior.  Chimney/skylight step flashing -- Chimney flashing can leak if high winds pull it away from your chimney or roof, or if the sealant is compromised. Skylights are trickier to diagnose.