What does the mark mean?

[latitude and longitude network]

A ruler on glass or other transparent materials on the focal plane of a telescope or other optical instrument, used to locate and measure objects and explain dialects in detail. Grain heading Ye Zi's "Harvest" I: "Look at the ground, all the seedlings have roots and buds, and they will be marked soon. After blowing the old south wind for two or three days, you can see the millet in Huang Cancan. "

Word decomposition

The end of the tree extends to the surface, not the root: the specimen. Treat the symptoms, not the root cause. Mark: trademark. Road signs. Mark. Sign. Ruler's slogan To express in words or other things: express. Title. Price tag. Advertise (originally for revealing and displaying; Later extended to propaganda and boasting). A thread is a slender thing made of silk, cotton, hemp and metal. Can be twisted at will: silk thread. Cotton thread. Coil. Wire cord Geometrically, it refers to a figure formed by the arbitrary movement of a point: a straight line. Curve. Lines. Something similar to a line: light. Sight. Clue (a clue or clue to something)