what is the naming convention around s_ in solidity

Question

I have seen staking balances using s_balances in contracts.

However, I tried searching around and I could not find the answers.

what is the naming convention around s_ in solidity?

Answer 1

s_ for "storage".

The s_ is a convention that seems to have been first adopted by the Chainlink developers (example) to indicate that a given variable is a storage variable, and therefore care should be taken in its use.

Answer 2

From what I have seen in Patrick Collisions Videos, the s_ is to notify developers that the computation on this data structure is gas-intensive.

For example

    // Account -> Token -> Amount
    mapping(address => mapping(address => uint256))
        public s_accountToTokenDeposits;

On such hashmaps, computations using them could be intensive, so devs would try to minimise changing the data in these datastructure.