This is a pictograph of a flag or banner. There is a similar symbol in the Naxi Dongba script. The banner would have carried writing. Hence, this symbol is associated with the transfer of information. The correct translation depends upon the context, and might be: the noun message; the noun news; or, the verb to announce.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-99 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 37: Collections in India: Suomalainen Tiedeakatemia.
Image Credit:
Indus Script Sign Number 402: Sign List of the Indus Script: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.