Is there any regulation on the rafter spacing of buildings?

In the roof structure of a wooden house with a tiled roof:

Purlins (logs or purlins) are placed on the roof truss and fixed with grasshopper nails, or placed on the "small beam" on the wall; Wooden rafts are nailed to purlins at equal intervals according to tile width, which is convenient for covering yin tiles (ditch tiles). The above is a small blue tile (cloth tile) roof structure. In the mechanical tile (flat tile) roof, the rafters are large tiles or thin roof panels. The spacing shall be properly laid according to the rigidity and flexibility of purlins and the thickness of rafters, and generally the spacing of 300 shall be appropriately adjusted. The spacing value and allowable error are not strictly specified.