You can add a "trade group" to any transaction on the „enter coins page“. It is just an additional sorting /grouping option for some reports we offer.
Adding a label to any of your API Job, which is an optional setting, will create a trade group as well for your imported transactions via this API job. So you could separate your API jobs e.g. for the "BTC Import" or "ETH Import" as all transactions from there are imported by default as "BTC Transactions" or "ETH transactions". See articles API Overview - Wallets and Exchanges or BTC and Altcoin Wallet API Import for more information.
You can change / add a trade group of more then one trade via the „bulk edit / delete“ option on the „enter coins page“.
Here you can choose which trades - sorted by exchanges, trade groups, dates etc - should be adjusted.
You can sort the "Balance by Exchange page" in the drop down for trade groups as well.
Best practice/recommendation/summary:
1. Trade Group Names should not be too long ( limited to 60 characters)
2. Not too many different trade groups (below 50) due to potential performance issues in some reports
3. Could be used as condition for bulk/edit delete: Bulk Edit and Delete transactions
4. Could be used as filter for some Reports
5. Trade group "swap" is mandatory in case of token swaps/splits and then you cannot add any other trade group name: VEN into VET Swap - trade group "swap" feature