Additional sheath: Second part of a wall composed by two zones (carcass + sheath).
Inner wall: Internal part of the skeleton, separating central cavity and skeletal structures, composed by a porous carcass, simple or coated by an additional sheath.
Outer wall: External part of the skeleton, composed by a porous carcass, simple or coated by a additional sheath.
Single wall: External part of the skeleton for one-walled cup, composed by a porous carcass, simple or coated by a additional sheath.
structure | |_ Additional sheath | |_ Type of additional sheath (IW) {None , Present on outer wall (or single wall) , isn't included in the term} | |_ Type of additional sheath (OW/SW) {None , Present on inner wall , isn't included in the term}