Vertical intervallar structures: Longitudinal and often radial structures inside the intervallum (septa, taeniae...).
Intervallum: Space enclosed between the walls.
Vertical intervallar structures | |_ Type of vertical intervallar structures {None} | |_ Repartition of vertical intervallar structures pores {None} | |_ Porosity of vertical intervallar structures {None} | |_ Pores of vertical intervallar structures {None}