What is the difference between Type I hex nuts and special-purpose nuts?

Found online, for reference. The main difference between the two is their height; the type 2 nuts are thicker than those of type 1. GB3098.2 specifies exact dimensions for these nuts. Type 1 corresponds to the product GB6170, while type 2 corresponds to the product GB6175. Hex nuts of type 1 are the most widely used. Grade C nuts are used in machines, equipment, or structures with a relatively rough surface and lower precision requirements; Grade A nuts (suitable for thread nominal diameter D ≤ 16 millimeters) and Grade B nuts (suitable for thread nominal diameter D > 16 millimeters) are used in machines, equipment, or structures with a smoother surface and higher precision requirements. Type 2 hex nuts, which are thicker, are commonly used in situations where frequent installation and removal are required. Hex nuts with a thin thickness are often used in situations where space on the surface of the components to be connected is limited; they are also commonly used as lock nuts to prevent the main nut from loosening. The height of Type I nuts is 0.8d, while that of Type II nuts is 1.0d. Regarding its scope of use: Type I is suitable for 1) nominal pressure classes of less than or equal to PN40; 2) non-toxic, non-flammable media, as well as applications without intense cycling. In addition, special-grade fully threaded bolts and Type II hex bolts should be used. For specific details, refer to HG/T 20613-2009