I don't think it's been identified. However, she is a long-serving Starfleet officer, and was both a Chief Fleet Inspector and a (probably senior) instructor at Starfleet Academy before joining the Enterprise, so you could make a reasonable guess that it's a badge of seniority/advanced qualification.
I don't think it's been identified. However, she is a long-serving Starfleet officer, and was both a Chief Fleet Inspector and a (probably senior) instructor at Starfleet Academy before joining the Enterprise, so you could make a reasonable guess that it's a badge of seniority/advanced qualification.