After the arrival of the computer age, the ATSF gave every track a number along with spots along each track. They called these Car Location Identification Codes or Car Location Inventory Control. Both are official ATSF designations. The earliest in my personal collection date from 1980.

The CLIC above dates from 1985. The tracks were designated as follows:

2601	Moline east leg of wye
2602	Moline west leg of wye
2603	Moline pass (yard track)	60 Cars
2604	Moline yard track	50 cars
2605	Moline yard track	50 cars
2606	Moline yard track	19 cars
2607	Moline standard spur
2608	Moline pocket track
2609	Moline house track
2610	Moline Webb spur
2611	Moline yard track	30 cars
2612	Moline roundhouse track	3 cars
2699	Moline main line