What lines aren't used when in linear perspective?

In linear perspective, the lines that aren't used are those that don't converge at the vanishing point, such as vertical and horizontal lines that run parallel to the picture plane. These lines maintain their direction and do not recede into the distance, unlike receding lines that lead to the vanishing point. Additionally, any lines that create depth without following the perspective rules, such as arbitrary or skewed lines, are also not utilized in creating the illusion of three-dimensional space.