# Feature References

Use the resources in this section for support using the Gateway features:

* [Request Checking Only](https://guides.gitbook.io/integrationguide/references/feature-references/request-checking-only)
* [Merchant Account Routing](https://guides.gitbook.io/integrationguide/references/feature-references/merchant-account-mapping)
* [Velocity Control System (VCS)](https://guides.gitbook.io/integrationguide/references/feature-references/velocity-control-system-vcs)
* [Duplicate Transaction Checking](https://guides.gitbook.io/integrationguide/references/feature-references/duplicate-transaction-checking)
* [Capture Delay](https://guides.gitbook.io/integrationguide/references/feature-references/capture-delay)
* [Card Identification](https://guides.gitbook.io/integrationguide/references/feature-references/card-identification)
* [Integration Testing](https://guides.gitbook.io/integrationguide/references/feature-references/integration-testing)
* [Sample Signature Calculation](https://guides.gitbook.io/integrationguide/references/feature-references/sample-signature-calculation)
* [Transaction Life Cycle](https://guides.gitbook.io/integrationguide/gateway-functionality/payment-methods/paypal-transactions/transaction-lifecycle)
* [Transaction Types](https://guides.gitbook.io/integrationguide/references/feature-references/transaction-types)
* [Payment Tokenisation](https://guides.gitbook.io/integrationguide/references/feature-references/payment-tokenisation)
* [Transaction Cloning](https://guides.gitbook.io/integrationguide/references/feature-references/transaction-cloning)
* [Credentials on File Matrix](https://guides.gitbook.io/integrationguide/gateway-functionality/features/credentials-on-file)
* [PDS2 SCA Compliance](https://guides.gitbook.io/integrationguide/references/feature-references/psd2-sca-compliance)
* [Hosted Payment Page Options](https://guides.gitbook.io/integrationguide/references/feature-references/hosted-payment-page-options)