This question has two parts:
Can someone propose a sufficiently general tag wiki for trace? Click through to the tag to see what questions are currently tagged there (in particular, I am not sure how to include the one about Connes/Weil's trace formulae or the one about Galois theory). I am imagining the trace to contain the linear algebraic trace and its direct generalisations; I hope that is reasonable.
Trace has some other meanings in mathematics; at least three others appear in Wikipedia: field trace, trace operator in analysis (which is like a restriction operator, but for restrictions of certain measurable functions to certain measure zero sets...), and trace monoid. Which of these should be included in the trace and which should be split off?