Every two weeks, ten tokens are put up for a community vote. The top 4 tokens are chosen and then will become tradable on Ethfinex.
Voting happens using 'Ethfinex Voting Tokens'. These tokens are distributed to Nectar Token (NEC) holders every time a vote starts based on the number of the tokens which that user held on the date the vote began.
For example, if you hold 10,000 NEC on the date of the vote beginning, you also receive 10,000 Ethfinex Voting Tokens (EVT).
EVT are spent when voting for one of the tokens on the list. All remaining EVT not used in voting expire at the end of the two week period and the EVT markets on Ethfinex are then cleared. Users will be required to vote or sell the EVT before expiration to avoid any loss. Tokens withdrawn to external wallets will also expire and balances will disappear at the end of the vote. This is automatic and will expire across all Wallets. EVT are then reissued based on user's updated NEC balances to be used in the next token listing vote and the EVT market begins again.
You can monitor the currently ongoing vote on the nectar.community site.
This system allows Nectar token holders to easily vote from their own Ethereum wallet, or delegate or sell their votes to new members or those who wish to support a particular token on the list without selling or spending their Nectar tokens.