Next week I'll have to visit someone in Porto and hand him an iPhone 11 which is a gift from his father. He is a visitor to Portugal himself. He provided me with a very unusual address.
Rua Justino Teixeria n 77 1o tras 4300-279
I figured out that 4300-279 is the post code and used Google to find a close address in case he messed up the format and I found something on booikng.com
Rua de Justino Teixeira nº640, Campanhã, 4300-277 Porto, Portugal
So (Rua de Justino Teixeira) is the address but what is with the (n, o and º) symbols?
To make things more complicated he moved from what I assume is a short-let flat to another address
Praceta quinta da bela vista 133 1o dto 4400-261 Vila Nova de Gaia
I find the (1o) to be the most confusing part unless he made a mistake