What do k and n stand for in the representation of steel bars on building cardboard?

Distribution bar symbols of structural plates usually include: k, m, g and n, which respectively represent the spacing: width, width, medium and dense (which can be understood in this way). For example, in a flat drawing, distribution bar symbols are displayed as K8, M8, G8 and N8, as shown below:

1, where k represents the width, the approximate spacing is @200, and 8 is the distribution rod with a diameter of 8 mm ..

2, m stands for width, and the approximate spacing is @ 180, and 8 is a distribution rod with a diameter of 8 mm ..

3, G stands for moderate distance @ 150, and 8 is a distribution bar with a diameter of 8 mm ..

4, n stands for density, the approximate spacing is @ 100, and 8 is a distribution bar with a diameter of 8 mm.

The above is my personal understanding, I hope it will help you.