| _BookData | Internal data structure of Bookmark Engine |
| _Engine | Structure describing particular dictionary |
| _FilePart | Internal data structure for representing part of file |
| _SDData | Internal data structure of XDXF Engine |
| _TarHeader | Structure of entry in tar header |
| _WSDBusData | This structure contains data vital for DBUS communication |
| _WSDBusMethodData | |
| _WSMngSearchAtom | Structure holding all data for each thread to properly run |
| _WSMngSearchData | Structure holding all data needed by manager to work |
| _XDXFCacheData | Structure to help make optimization possible |
| _XDXFCheckingData | Structure used while dict_eng_module_check() is working |
| _XDXFData | Internal data structure of XDXF Engine |
| _XDXFWordsListData | Structure to help parse xdxf file for searching words list |
| _XDXFWordsTransData | Structure to help parse xdxf file for searching word's translation |
| EngineModule | Global functions structure |
| HtmlLayout | Struct which manage layout of html (translation) area |
| WSGuiAppData | Struct which contains all components of application |
| WSGuiList | Struct which contains components of words list |
| WSGuiMenu | Struct which contains components of menu |
1.5.1