Interactive Brokers does maintain the use of creating contracts in both the Trader Workstation and Client Portal APIs. The default structure will allow the individual to typically reference the ticker symbol, security type, exchange, and currency; however, the best practice recommended by Interactive Brokers for both platforms is to use only the contract identifier, or ConId, and the Exchange instead. This will cover a complete contract without the need for additional parameters.
These conids are static for each and every contract and will never change. Values such as 265598 for AAPL will always remain as the AAPL contract identifier for the underlying stock contract.