This working paper argues that SignWriting requires writing-system analysis to ask not only what writing represents, but how the primary written unit is organized for reading. Sutton SignWriting is presented as a strong case of plane-based writing because writers select symbols and compose them spatially inside a written sign. Existing typologies remain useful, but SignWriting exposes limits in approaches shaped mainly around linear written traditions. The paper proposes a two-part typological question: what does the writing represent, and how is the written unit organized? This document DOI record includes the point-line-plane evidence notes as a companion packet file for the working paper.
Steve Slevinski (Mon,) studied this question.