Short North !
CC line = ?Central Coast line eg North Strathfield to Newcastle.
NCL = North Coast Line or Newcastle or something else?
CC, is a fairly common term these days especially when news channels refer to train running within the general district from the Metro area to Wickham/Newcastle interchange. Also part changing and referrals to the Central Coast lines are announced on regional news as Central Coast line for delay and on time type of running's. CC was used for commuter trains running as far as Gosford and later extended to include Wyong services. Both being terminating/turn round stations for trains each way.
Short North has not been a term used these days very much. In the older days especially when engine changes were carried out out at Gosford, other words prior to the NCL line being the more common short term name for the line meaning NCL being for NewCastle Line. A similar tag was applied for trains from Sydney to Goulburn being deemed Short South, the likes of the Illawarra and the Western line had other tags such as the mountains for the line to Lithgow, and the Illawarra being deemed nothing more than The coast, or Illawarra.
These days, with through running on trains heading out of Sydney and going through Broadmeadow and heading to Werris Creek or the North Coast Line, and they do not have engine changes or crew changes until Taree and WCK are reached.
The crews working colies as far as the Ulan line and other collieries are just deemed as being "The Valley" working.