Minecraft – Hidden blocks on Debug mode – Minecraft

minecraft-java-edition

I found these weird blocks in 15w51b snapshot. I used Debug mode and at the end, I found these weird blocks in this snapshot.
Can I use these in my world?
I gonna take a picture for you guys to check it out!
Weird Blocks

Best Answer

The blocks stand for the following:

D = Data
L = Load
C = Corner
S = Save

Usage:

When obtained with the /setblock command, structure blocks do not have any use in game, and emit a light level of 15. However, they are used internally by developers to create structures. They were used to create the end city dungeon structures.

Minecraft Source: http://minecraft.gamepedia.com/Structure_Block