Can any body please explain this statement from the "Nursing Fundamentals" to me!

I think it means using the "twelve hour clock" positional analogy as a charting device for describing where something (bruise, wound, etc) is on a pt's body.

From wikipedia:

A clock position is the relative direction of an object described using the analogy of a 12-hour clock. One imagines a clock face lying either upright or flat in front of oneself, and identifies the twelve hour markings with the directions in which they point.

Using this analogy, 12 o'clock means ahead or above, 3 o'clock means to the right, 6 o'clock means behind or below, and 9 o'clock means to the left. The other eight hours refer to directions that are not directly in line with the four major directions.

One example that I saw in my HH experience in school. I was observing the HH nurse measure a pressure ulcer. She charted "depth 3 cm at the 12 o'clock position, 1.5 cm depth at 3 o'clock, 2 cm at 6 o'clock..." etc.

Another example could be "1 cm laceration at the 9 o'clock position of the left breast."

The head of the person is at 12:00, the feet are at 6:00.

If you have a sacral wound with tunneling, it would be described as "tunnel at 4 o'clock is 2cm deep" Does that make any sense?

Here's another example: I have a visual field deficit from surgery that I had ten years ago. The official name is "homonymous left superior quadrantanopia" but it is often more easily understood if I say "I have no vision from 9:00-12:00 in either eye."

This is yet another aspect of how the digital clock affects learning. When a kid has only seen "12:18" on a clock, s/he has no idea what that looks like on an actual, like, dial.