The origins of Indus writing can now be traced as far back as the Ravi Phase (c. 3300-2800 BCE) at Harappa. Some inscriptions were made on the bottom of the pottery before firing. Other inscriptions such as this one were made after firing. This inscription (c. 3300 BCE) appears to be three plant symbols arranged to appear almost anthropomorphic. The trident looking projections on these symbols seem to set the foundation for later symbols.