Whenever something goes around something else, either literally or figuratively, partially or completely, this glyph marks the end of the area. It is often paired with the symbol for to wrap. When it is not paired with wrap, the glyph translates as the noun end.
The symbol probably shares a common root with the Chinese character xì 匸, which means to conceal or cover.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-331 b: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 84: Collections in India: Suomalainen Tiedeakatemia.
Comment:
Side b of seal impression M-331 should be read first. Mahahadevan's sign number 299 is followed by sign number 98. The literal reading is end place. In other words, it is the verb to arrive or the noun arrival.
Image Credit:
Indus Script Sign Number 299: Sign List of the Indus Script: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.