drawing red lines; redlining
General act of drawing lines in red ink, often for emphasis or correction.
The teacher drew red lines on the exam paper to point out mistakes.
red lines marking town limits (Edo period)
Historical term for red boundary lines drawn on maps to indicate town or district limits during the Edo period.
red lines marking nouns in kanbun texts
Archaic use: in classical Chinese texts read by Japanese scholars, red lines were drawn beside nouns to aid parsing.
On maps from the Edo period, red lines were drawn to show town boundaries.
In the Japanese reading of classical Chinese, red lines were sometimes added next to nouns to make them easier to read.
Standard kanji spelling.
Variant spelling; less common than 朱引き.
Compound of 朱 (しゅ, 'vermilion, red') and 引き (ひき, 'drawing, pulling'), from the verb 引く (ひく, 'to draw'). The exact historical derivation is uncertain, but the term straightforwardly describes the act of drawing with red ink.