Image: Iravatham Mahadevan
Image: Iravatham Mahadevan

If you modify an Indus symbol by adding one point of light at each of the cardinal points, it means that it is true everywhere. This is the noun method or way surrounded by four points of light. Hence the translation is custom (or practice) everywhere.

Illustrative Text Reference:

Mohenjo-daro: Seal: M-1369 a: Sayid Ghulam Mustafa Shah and Asko Parpola, 1991: Corpus of Indus Seals and Inscriptions: Volume 2: Page 179: Collections in Pakistan: Suomalainen Tiedeakatemia.

Image Credit:

Indus Script Sign Number 250: Sign List of the Indus Script: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.