A waterproof material installed at critical points in masonry walls to direct water out of the wall system. Flashing is typically installed at the base of walls, above openings, and at other locations where water penetration is likely. Proper installation of flashing is crucial for preventing water damage and ensuring the longevity of masonry structures.
http://www.wikidata.org/entity/Q647584, https://en.wikipedia.org/wiki/Flashing_(weatherproofing), https://www.google.com/search?kgmid=/m/0968pp&hl=en