What does this mean on car seat?

ri

I have the Chico key fit 30 and just noticed this and my baby is 2months and was born 5lbs and at his 2week checkup he was almost 8lbs. And he’s gotten way heavier since then and chunkier so im pretty sure he’s more than 11pounds. What’s does that little sign mean in the car seat? Do I need a new one or something im a little lost.

Sorry ladies I forgot to add picture