Characteristics
The writing system is largely pictorial but includes many abstract signs as well. The script is thought to have been mostly written from right to left, but sometimes follows a boustrophedonic style. The number of principal signs is about 400-600, comparable to the typical sign inventory of a logo-syllabic script. The prevailing scholarly view maintains that structural analysis indicates that the language is agglutinative, like the Dravidian languages.
According to a paper by researchers doing a comprehensive analysis of Indus signs at TIFR and published in the Korean journal Scripta, it took a significant time and effort, intellect, aesthetics, detailed planning and care to design the Indus script. It was acceptable all across the civilization and combining signs or combining signs with modifiers seems to have been done at all sites.
Read more about this topic: Indus Script