Shapes can be described using a set of landmarks. A landmark is a point of correspondence on each object that matches between and within populations. - Dryden, 2016.
form=size+shape is the geometrical information that remains when location and rotational effects are removed from an object. - Dryden, 2016.
Shape is the geometric information that remains when location, scale and rotational effects are removed from an object. - Kendall, 1977
