What are Namespaces and why do they matter?
Namespaces represent a unique identity for each of your accounts and assets on the blockchain. Similar to a web domain, you can choose a name you want associated with an account or asset. Then you can use that name as an address, providing a convenient human-readable way for people to see that you are who you say you are. You can also link the name to a token or other asset you have created. If you already have namespaces on NEM NIS1, you'll probably want to opt-in with them to prevent someone else from claiming your namespaces on Symbol later.
What are VRF keys and why do they matter?
VRF keys (Verifiable Random Function) are a needed part of the harvesting process. They ensure that it's impossible to predict which account will harvest the next block. They are used as part of an approach to avoid deterministic harvesting (where it is possible to predict and attack the node that is due to harvest next) by making node selection verifiably random. Opting-in with your VRF keys will ensure your Symbol account can continue harvesting just as your NEM NIS1 account. If you don't migrate them, you may need to transfer your XYM to a new Symbol account in order to begin harvesting.
Is there a minimum balance I need in order to Opt-in?
The minimum balance that must be held in an NEM NIS1 blockchain account at Snapshot is 100 XEM. Anything less than this will be excluded from Opt-in.
Can I Opt-in with a Trezor account?
Yes, you can.
Can I add multi-signature or add a namespace once I’ve opted-in?
Once you have opted-in an account you cannot opt that account in again. If there is an urgent requirement to add a namespace or you need to change account type please contact NEM Helpdesk.
What happens to XYM tokens that are not claimed via Opt-in?
At Symbol launch, these XYM tokens will be transferred to a Special Purpose Vehicle (SPV) and held on trust (see declaration below) so that the rightful owners can claim them post launch. Any unclaimed tokens after 6 years will be burned as per the community vote, reducing Symbol total supply.
Is there a hash to verify the downloaded file?
You can use the Checksum details below to verify the file for damage, modification and to prevent phishing.
The checksum for the NEM Desktop Wallet (Opt-in version) can be found here: https://github.com/nemgrouplimited/NanoWallet/releases/tag/2.4.7-optin
Checksum hash can be verified programmatically or by using third party tools (e.g https://www.appdevtools.com/checksum-calculator)
I'm unable to opt-in using Trezor. The error "Window blocked" is shown.
Please check that your browser has not blocked pop-up windows. The message about blocked pop-ups is presented in most browsers in the right part of the address bar. You need to click it to allow pop-ups. When trying again to opt-in, remember to back up your mnemonic (paper wallet) because each time new mnemonic is generated.
How to opt-in using NCC (old wallet)?
Opt-in service is not available for NCC. This wallet is discontinued. You need to export the wallet from NCC to the NEM desktop wallet.
How I can check that my opt-in is successful?
When you open the opt-in service again, it should present the success view. Your address on the Symbol network will also be visible. Please make sure you have a mnemonic backup corresponding to this address.