The starting point for this Indus sign is the ideograph for a walled corner pitch with the dimensions two Indus units by two Indus units. An extra line has been added which divides the corner in two. Hence, this symbol is the noun half corner pitch.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-119 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 41: Collections in India: Suomalainen Tiedeakatemia.
Image Credit:
Half Corner Pitch: Lynn Fawcett, 2018.