Picture a surface — a road, a wing, a page — with something visible left on it. Someone painted it, printed it, or wrote it there, and now anyone who looks can read it: stop here, this one is ours, this is the pattern that tells you which animal you are looking at. That visible thing left on a surface is one half of the word. The other half is the act of putting it there, hour after hour, one item at a time.
Wiktionary derives marking from Old English mearcung, that is mark plus -ing. The -ing ending can name an action or the thing an action leaves behind, which is why the word sits on both sides at once.
Wiktionary 記載 marking 來自古英語 mearcung，拆開就是 mark（做記號）加上 -ing。-ing 這個字尾可以指動作，也可以指動作留下來的東西。所以這個字從一開始就同時含著兩層：打記號的過程，和打完之後留在那裡的記號。
Wiktionary entry for marking (packet source_ref kaikki:3f6f69a190036ae4:1100139063:5480)
Three branches
留在表面上、看得見的記號
這一族直接就是核心畫面本身：東西的表面上有看得見的圖形、線條或字。差別只在那個記號是人弄上去的，還是天生長出來的。
noun · B1
Lines, letters, numbers or shapes that someone has painted, printed or written on the surface of something, especially a road, an aircraft, a vehicle, a floor or a wall, so that people can see them and know what the thing is or where to go.
標線／標記
把記號打上去的那段工作
核心畫面的另一半：不是看那個記號，而是做那個動作。老師在一頁一頁的作業上打勾、寫分數，做的就是一整晚的「打記號」。
noun · B2
The work a teacher does when they read students' written work, check it, and decide what mark or grade it should get. The source labels this use especially British English.
批改作業／改考卷
球場上的盯人
這一族離核心比較遠，用的是另一種「記號」：你把某個對手標成你的人。這是教學上的聯想，不是歷史來源的主張。
noun · B2
In team sports such as football and basketball, the job of staying close to one player on the other team so that they cannot receive the ball or score.
盯人防守
以下是外部詞典記錄的用法，原文照列，我們還沒有寫成教學內容。上面的說明才是我們自己寫的；有些用法可能上面已經講過了。
markingnoun詞源 1/ˈmɑɹkɪŋ/
The action of marking.
A mark.
The characteristic colouration and patterning of an animal.
A symbol or set of letters used to identify the type or identity of an object.
graph-theorymathematicssciencesAny configuration of a Petri net with a number of marks or tokens distributed across it.
這個拼法也被記錄為下列字的變化形：
資料來源：英文維基詞典 English Wiktionary（CC BY-SA 4.0）。 原文照列，未經改寫。