In the past, the sketch artist turned the sketch into a base map, and then dried the base map into a blueprint. Now some formal projects are still implementing blueprints, but this basemap is not drawn by hand, but printed directly by CAD. That's what the symbols here mean. However, there are different requirements for the content of this missing person column, and there is no unified national regulation. However, there are still specific provisions on other main requirements of CAD drawing. Please refer to relevant national standards GB/T 186 17.

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