Reusable three-arrow sign, which is the sign on the carton. What do the middle English RE~Y and the number 4 127 at the bottom mean?

No, as long as it is recyclable. This icon has two meanings:

First of all, it reminds people that after using and packaging the goods printed with the logo, please send them for recycling instead of throwing them away as garbage.

Secondly, it shows that commodities or their packaging are made of renewable materials, so it is beneficial to the environment and the earth.