The inscriptions are thought to have been written mostly from right-to-left (because there are several instances of the symbols being compressed on the left side, as if the writer is running out of space at the end of the row there), but they sometimes follow a boustrophedonic style. The number of principal signs is about 400. Since that is considered too large a number for each character to be a phonogram, the script is generally believed to instead be logo-syllabic.