The Galactic Empire: An Empire Reborn
Imperial Officers' Manual
Major Revision: 2.0 – 2008.10.31
An adaptation of the pre–Endor document and policies.
cylinders  RIP  cylinders
... A Line Captain's Rank Insignia ...

The rank of Line Captain (CL) is afforded to officers holding the position of ship captain onboard vessels of the Imperial fleet...

The rank is marginally superior to that of Captain, and in use on "large-scale" capital ships (those with fighter capacities of at least one full wing (6 squadrons/72 pilots))... Line Captains will typically be selected from the most capable & distinguished Captains.