The Sector Ipai Relay Log
Sector 5561 was a region of space.
In 2369, this sector was named on the chart Sector Ipai Relay Log – Relay Message Flow 1293 in Relay Station 47 Ops. The USS K'Warko was in this sector. (TNG: "Aquiel", production art)
Later that year, this sector was again named on the chart "Sector Ipai Relay Log – Relay Message Flow 1293" on Ohniaka III Research Station Ops. (TNG: "Descent", production art)
This sector was only mentioned in writing.