This is a very basic flag. The civilian flag of the Fourth Roman Republic. Government, military, and important families have variations on this flag on their standards, usually in silver. Various other tassels and figures are added in these variations but in the 28th century AUC silver is the preferred metal/color. Some of the truly ancient family lines still favor gold trim and emblems on their standards.
I hope to create some short fiction to develop this world in the next week or so.