In etherscan.io, under the TOKEN drop down menu, there is a list of tokens, and it is indicated that they all are ERC20 standard tokens
1) How do they get listed? Do we have to register a new ERC20 token somewhere or are they automatically recognized by etherscan?
2) If I add an extra function to an ERC20 standard contract, for example:
function mint(uint256 _amountToMint) {...}
Is the new contract still an ERC20 contract ?
Etherscan's FAQ page answers your first question in the "Token Tracker Listings" section. Here is what it says:
Any compatible ERC20 tokens on the Ethereum blockchain can be publicly and transparently tracked via https://etherscan.io/token-search
In addition to the above ERC20 token tracker, we also have a selected list of tokens at https://etherscan.io/tokens. The decision to list these tokens here are based on the following criteria, but not limited to :
- Token Popularity and Demand (important)
- Supported by a large exchange (i.e Poloniex, Kraken, Coinbase)
- Has a unique proposition/utility
- Visible website, about us, team page, company mailing address, official support channels like reddit, twitter, slack, facebook.
- Fully ERC20 compliant (https://github.com/ethereum/EIPs/issues/20)
- Is NOT a ponzi, pyramid, mlm or other similiar schemes
You may request for a token to be added on the https://etherscan.io/tokens page by filling up the following form https://docs.google.com/forms/d/e/1FAIpQLSe9t2VBwje7zO_xMKT3bO92H8nrzsQJCu2KeFU3PLgAjRONLA/viewform , however the ultimate decision will be at our own discretion.
A ERC-20 standard token, is a token that implements at least all the functions listed here: https://theethereum.wiki/w/index.php/ERC20_Token_Standard
All the ERC-20 tokens listed, have done at least one Token Transfer Events.
For example, take a look at this ERC-20 token (BAT) : https://etherscan.io/address/0x0d8775f648430679a709e98d2b0cb6250d2887ef#code
it implements all the ERC-20 functions, plus others like refund() and finalize().
A possible solution for testing if is an ERC-20 token could be this: first deploy your token locally, and then try to add it on MEW (you should connect MEW to the local network).
