Key Area of the letter “X” & the concept of “key areas”
There are lines and and areas inside of a letter shape which are crucial for recognizing the letter. These areas are so called “key areas”. They should never be covered by other elements, shapes, serifs or letters. Especially in advanced drawings, which are often very abstract, the letters will still stay recognizable, if you follow this rule. The cuts in the main shape of the letter “X” make it easier to recognize and are key areas as well. They are not explicitly needed to make it readable though. The key areas of the letter “X” are shown in the image below.