A glycan structure is built by adding new residues to the existing ones. The residues are always added to the last selected residue. If no residue is selected a new structure is created and the residue is added to it. A residue can be inserted before the current selection by clicking on "Structure -> insert" residue before or from the corresponding entry in the popup menu. The type of the reducing end of a structure can be changed by clicking on "Structure -> change reducing end type". In this way labels and markers can be added to the structure. The mass of the marker is added to the total mass of the structure. Fuzzy structures with uncertain antennae positions can be created by adding a bracket to a structure. The antennae can then be added to the structure by selecting the bracket.