Here are the data structures with brief descriptions:

Cfds_evt_t	An FDS event
Cfds_find_token_t	A token to keep information about the progress of fds_record_find, fds_record_find_by_key, and fds_record_find_in_file
Cfds_flash_record_t	Structure that can be used to read the contents of a record stored in flash
Cfds_gc_data_t
Cfds_header_t	The record metadata as stored in flash
Cfds_op_t
Cfds_page_t
Cfds_record_desc_t	The record descriptor structure that is used to manipulate records
Cfds_record_t	A record to be written to flash
Cfds_reserve_token_t	A token to a reserved space in flash, created by fds_reserve
Cfds_stat_t	File system statistics
Cfds_swap_page_t
Crd_sensor_configuration_t	All sensors must implement configuration functions which accept this struct
Crd_sensor_data_bitfield_t	Bitfield to describe related sensor data
Crd_sensor_data_fields_t	Union to access sensor data
Crd_sensor_data_t	Generic sensor data struct
Crd_sensor_t	Interface to sensor. Some sensors can implement additional functions. The additional functions are defined in the interface of the sensor
Crd_test_gpio_cfg_t	Structure to configure GPIO test with input and output. These GPIOs must be physically connected on board
Cri_adc_channel_config_t
Cri_adc_config_t
Cri_adc_get_data_t
Cri_adc_pin_config_t
Cri_adc_pins_config_t
Cri_adv_scan_t
Cri_comm_channel_t	Control API for communication via outside world
Cri_comm_dis_init_t
Cri_comm_message_t	Application message structure used for communication
Cri_gpio_evt_t	Event from GPIO
Cri_i2c_init_config_t
Cri_lis2dh12_dev	Context for LIS2DH12
Cri_power_regulators_t	Enable implementation selected by application
Cri_radio_channels_t	Bitfield to describe related sensor data
Cri_spi_init_config_t
Cri_uart_init_t	UART initialization data
Crt_adv_init_t	Initial configuration for advertisement. PHY will be transferred to GATT.
Crt_button_init_t	Struct for initializing buttons
Crt_sensor_ctx_t
Cruuvi_interface_uart_init_config_t