I discovered that there is a little-used tag "ptc" which appears to be used for questions involving polyfuses (Polymeric Positive Temperature Coefficient devices). The tag "pptc" is already a synonym for polyfuse. Should "ptc" be as well?
Edit:
The barrier to entry isn't really the merging part, but the synonym. Due to the way the StackExchange is set up, synonyms are really hard to put in place without moderator support.
Perhaps suggesting a synonym is less ideal than just retagging the questions; however, at my company, we usually refer to polyfuses as "PTCs" so perhaps it is a common usage?
Is it better to simply retag questions?