Sign Decal Corrugated Metal 6x1
It's a sign. You write things on it.
Harvest drops
Iron× 10
Taken apart with a harvesting tool (axe, pickaxe, shovel), before perks and tool bonuses.
When it collapses
Falling, it leaves 
Scrap Metal Pile (60% of the time) where it lands.
Where to find (21 POIs)
Diamond's Mens Club (tier 4), Holvez Rent-a-Car (tier 4), Stand Tower (tier 4), Super Shamway (tier 4), 4 Ever Video (tier 3), Ballzstrike Bowling (tier 3), Buy-N-Go Apartments (tier 3), Downtown MeltDowns (tier 3), Law & Order Square (tier 3), The Rejekts Gang Outpost (tier 3), Collision Center (tier 2), Downtown Evacuation Point (tier 2), Buy-N-Go Rest Stop (tier 1), Jerry's Fill (tier 1), Circuit Splits Station, Navezgane Bus Terminal, Navezgane Outlets, Navezgane Public Library, Patriot Pavilion, Shines Jewelry, Trader Hugh.
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.