does anyone know the meaning of  "dos Reales Cedulas" ?

curious minds need to know,

joseph

ps: Enclosed for your amusement are some pictures of a 1793 1/2 Real
Coin that was used as legal tender in Mexico though I believe it was
minted in Spain. I paid $30 for it and the date is a little hard to read
but it has special meaning to me because it was something from the same
time period that my GGG Twin *Grandfathers: Thadeo Diaz were born in
Colotlan.

*my paternal grandparents were 3rd cousins and one came from one twin
and the other from the other twin.