LINE n.
Course of conduct, thought, occupation, or policy; method of argument; department of industry, trade, or intellectual activity. He is uncommonly powerful in his own line, but it is not the line of a first-rate man. Coleridge.
MANAGEMENT n. 2 definitions
art of managing; the manner of treating, directing, carrying on, or using, for a purpose; conduct; administration; guidance; control; as, the management of a family or of a farm; the management of state affairs. "The management of the voice." E. Porter.