A Multisim component has a label and a RefDes (unique SPICE identifier). Both can serve as a "name" and can be changed through the components properties dialog (select tab "Label") or the spreadsheet view (not available in all Multisim tiers).
In genreal I would recommend to keep the RefDes simple (e.g. R1, Cout, D13, etc.) and use the label for labeling and documentation.
Regards
Ingo Foldvari
Area Sales Manager - US West Academic
National Instruments