An indicator line is a type of line or mark that shows or suggests something. It gives us information or clues about a specific situation or condition. Full definition
These custom support resistance indicator lines show decent places to enter or exit. (tradingview.com)
Fill the power steering fluid reservoir to the correct indicator line and reconnect the battery cables. (yourmechanic.com)
ex4 custom indicator line up below the 0.00 level as depicted on Fig. 1.1, price is said to be pushed somewhat lower, hence a trigger to initiate sell order (s). (fxtsp.com)