You can add, edit, and save properties of atoms, bonds, and molecule.
To add propertie(s)
Select the structure element(s).
Choose "Edit properties..." option from the contextual menu.
The added properties are saved files supporting properties such as MRV or SDF (in case of the molecule property only).
Atomic properties can be displayed setting Menu > View > Advanced > Atom Properties.
Bond and molecule properties cannot be displayed on the canvas currently.