Names are important and powerful in the show. Emma’s name was powerful enough to wake Rumple from the curse, for example. He collects them as a matter of course–Jiminy delivers both objects and the names of their owners. Rumple knows the name of Hansel and Gretel’s cursed father–possibly partly because he knew of the compass, or because it was right in front of him at the time. And he couldn’t find Robin Hood properly without both the bow and the name that he got from the Sheriff. The true name of the Dark One is written on the dagger and Rumple can apparently be summoned through his name (if he wants to be).
Just because he didn’t use it as a secret password to get out of Cora’s contract doesn’t mean they’re not really important and really powerful in the series.
Keeper of Belle's Gold magic, sand dollar, cloaks, purple FTL outfit, spell scroll, library key, copy of Romeo and Juliet, and cry-muffling pillow, Rumple's doll, overcoat, and strength, and The Timeline. My spreadsheet: https://drive.google.com/file/d/0B6r8CySCCWd9R0RUNm4xR3RhMEU/view?usp=sharing