The story
From war + chalk, modelled on war-dialing.
Etymology from Wiktionary, CC BY-SA 4.0.
Today it means: To draw chalk symbols in public places (such as the side of a building or a sidewalk) to show users of computers with Wi-Fi capability where a wireless network may be accessed. Full definition →
From war + chalk, modelled on war-dialing.
Etymology from Wiktionary, CC BY-SA 4.0.