1, if the drawing numbering rules require the middle of the break, such as the use of segmented numbering, then you can break in the middle of the numbering, this break is usually to distinguish between different parts of the drawings or to facilitate the classification and organization of drawings.
2, if the rules of drawing numbering does not require a break in the middle, then usually can not be disconnected from the number, so as to ensure the continuity of the number of drawings and uniqueness, easy to find and manage the drawings.