What does the double checkmark mean? [Risolto]

What does the double checkmark mean? Im confused on what it means. Does it mean multiple coins in your collection or?

One check mark means you have that coin type in your collection.  Two check marks mean you have all year lines of that coin in your collection.

Thank you!

https://en.numista.com/numisdoc/what-s-the-meaning-of-the-icons-on-a-coin-page-142.html