Red Line
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The Red Line refers to an imaginary border drawn around all space that the Colonials had charted, and marks the border between explored and unexplored space.
When attempting to escape the Cylons after their devastating attack on the Twelve Colonies, and with the future of 50,000 survivors on his hands, Commander Adama orders a Jump "beyond the Red Line" to the Prolmar Sector. The Red Line The Jump to Promar Sector was beyond the Red Line, likely indicating the border between charted and uncharted space.