Token Identifier

Tokens are identified with attribute-value pairs

In TokenScript, for each token, an instance of that token is identified by a key-value pair or a sequence of key-value pairs.

For Ethereum's ERC20 Tokens, a token is identified by its owner address since each address can only have one such token. For example:
ownerAddress=0xedd6d7ba0ff9f4bc501a12529cb736ca76a4fe7e
where 0xedd6… is the Etheruem address of this token's owner.
For Ethereum's ERC721 Token, a token is identified by the attribute tokenId. For example, the following is the identifier of a token:
tokenId=0x06012c8cf97bead5deae237070f9587f8e7a266d
It's the identifier of a CryptoKitty called Tzar Hulashorts (not that matters).

The attribute(s) that defines a token is called distinct attribute(s).

You do not need to confine to a specific ERC, such as the tokenID defined in ERC721. You can define a new token with suitable distinct attribute(s) that suits the nature of your token.

For example, for a car token, the distinct attribute might be vin, short for Vehicle Identification Number. So a car may be identified by:
vin=KL3TA48E9EB541191