What does `@` represent when dealing with Windows registry keys?

Question

What does @ represent when dealing with Windows registry keys?

Examples:

Answer 1

Looks like a broken import. When exporting to .reg files, @ is the (Default) value:

Windows Registry Editor Version 5.00

[HKEY_CURRENT_USER\Test]
@="Hello World"

In your case, the .reg file might have contained this instead:

"@"="Hello World"

That makes it a regular value like any other. The meaning is up to the software reading this particular registry entry either way. That being said, I also have this value, so it probably comes with Windows by default.

In the neighboring keys, you can see that this value is supposed to go into the (Default) value. Whether this means anything is broken I cannot tell.