Here are the data structures with brief descriptions:

_u8g_box_t
_u8g_dev_arg_bbx_t
_u8g_dev_arg_irgb_t
_u8g_dev_arg_pixel_t
_u8g_dev_t
_u8g_page_t
_u8g_pb_t
_u8g_t
biosParmBlock	BIOS parameter block
cache_t	Cache for an SD data block
CID
Com
Commands
csd_t
CSDV1
CSDV2
directoryEntry	FAT short directory entry
directoryVFATEntry
EEPROM
Extruder	Data to drive one extruder
fat32_boot	Boot sector for a FAT32 volume
fat32_fsinfo	FSINFO sector for a FAT32 volume
fat32BootSector	Boot sector for a FAT16 or FAT32 volume
fat_boot	Boot sector for a FAT12/FAT16 volume
FatPos_t	Internal type for istream do not use in user apps
GCode
HAL
masterBootRecord	Master Boot Record
partitionTable	MBR partition table entry
Printer
PrintLine
RFHardwareSerial
ring_buffer
ring_buffer_tx
RMath
Sd2Card	Raw access to SD and SDHC flash memory cards
SdBaseFile	Base class for SdFile with Print and C++ streams
SdFat	Integration class for the SdFat library
SdFile	SdBaseFile with Print
SdVolume	Access FAT16 and FAT32 volumes on SD and SDHC cards
TemperatureController
u8g_str_size_struct
UIDisplay
UIMenu
UIMenuEntry