Possession of LSULP tokens and the credit receipt allows for zero fee removal of liquidity if there is sufficient LSU Pool liquidity of the desired LSU tokens.
Here's some more details about this NFT:
It is soulbound
This means it remains in your wallet, cannot be moved and is associated with you and your LSU Pool activity.
It is burnable (by you)
The NFT is burnable. Since it is soulbound and cannot be moved, it is only burnable by you in your wallet.
Each wallet only needs 1 NFT
If you add multiple different LSUs over time you don't get multiple credit receipts. Instead the data associated with the NFT is updated to include new LSU balances.
Its data is updated based on your activity
Similar to above, if you remove liquidity or later add liquidity, the NFT data is updated to reflect that.