ERC223 tokens

ERC223 is backwards compatible with ERC20 meaning every software that supports ERC20 will also supports ERC223. In additions, ERC223 merges the token transfer function among wallets and contracts into one single function ‘transfer’. The biggest change is that ERC223 no longer allow token to be transferred to a contract that does not allow token to be withdrawn. Before ERC223, if someone send his/her token into a contract that has not allowed anyone to use it, the token will simply be locked and can never leave that contract. Because of this, hundreds of thousands of dollars’ worth of ERC20 token has been locked up. Merging functions can also save transaction fees in terms of gas.