Obligatory types of fields:
1. Structure - connectivity matrix and atomic screen coordinates, which are created by implanted original structure editor StrEd
2. Brutto-formula - calculated automatically from the structure
3. Molecular weight - calculated automatically from the structure.
Arbitrary types of fields:
4. Chemical structure - additional structure type field
6. Real + units - real numbers with a measure units
12. Calculated - the value is calculated from the mathematical formula
13. Function - calculated using mathematical formula, presented as diagram
14. Picture - graphical image
15. Object - standard Windows OLE type
17. Record - the group of fields mentioned
18. Packed Array - two dimensional array to store spectral information
19. WWWLink - calls defined URL
20. DataBase Link - calls addressed CheD database open on defined record.