EVM's SSTORE and SLOAD instructions access 256-bit words. At some cases, we want to store more data in a single storage slot. If we add more EVM instructions to support arbitrary-length data loading and storing, compatibility would be hurt. So a pseudo smart contract is preferred. This smart contract is psuedo because it is not implemented by EVM bytecode. Instead, it is supported natively in the full client, smartbchd. So it can directly use MoeingADS's arbitrary-length data storage. It has a predefined address: 10002.