The RF.h file defined a common union type for all the different flavors of radio setup commands as: {code} typedef union {     rfc_command_t commandId;     rfc_CMD_RADIO_SETUP_t common;     rfc_CMD_PROP_RADIO_SETUP_t prop;     rfc_CMD_PROP_RADIO_DIV_SETUP_t prop_div; } RF_RadioSetup; {code} Within the driver, fields were accessed through a casted of pointer: {code}  if ((pObj->clientConfig.pOpSetup->commandId.commandNo == CMD_RADIO_SETUP) ||     (pObj->clientConfig.pOpSetup->commandId.commandNo == CMD_BLE5_RADIO_SETUP))  {      ...  } {code} To be able to support BLE5 related setup commands, a new field was added to the union. {code} typedef union { ... rfc_CMD_BLE5_RADIO_SETUP_t ble5; ... } RF_RadioSetup; {code}