It's called a rocker, and I know some old school shapes used to employ it. Don't know what the functionality of it is though. @Mbrimson88 probably does.
Ha, just going through reading and then thought about those Consolidated boards that really had a significant rocker in them but I don't think that really took off. Maybe there was too much rocker action in those boards.
The Real Low Pro was maybe the most well known version of the rocker type construction, of which I had quite a few (even one still set up too and that thing will just NOT break, even though it is so super old and flexy now).
There was even an old thread on it too, which I found while looking through a normal search online, not searching on here, but also a couple of other articles and info which is interesting to read as well.
Real Low Pro (from 2011)
https://www.slapmagazine.com/index.php?topic=57637.0https://www.weartested.com/real-skateboards-low-pro-ii-decks/The Low Pro II technology is basically a center pressed production process which influences the shape of the deck. The deck is a centered rocker and thus, has a lower center of gravity which should increases control and pop. Through the tighter concave the decks using this technology offer improved strength and lasting pop. In addition, Real used stiffer x-bands and an exclusive new additive free glue in order to increase the strength and lightness. In summary, Real promises to offer more board control and strength with their Low Pro II technology.