Infoset keydate and tick box

Dear Experts,

I have a transaction data DSO left-out-joined to a master data attribute.

I am not sure what does the left most tick box mean and what is the purpose of it in the infoprovider as seen when you enter maintenance mode of the infoset. Also, there is a column called key date in the table. What is it for? In the master data attribute, i have valid-from and valid-to. Do I need to tick these are keydate? do i need to check the tick box?

regards

Pascal