Permission check mark icons become green squre icons. why?

When I try to set permission of a set of files or folders with WinSCP ver4.1.6, some of check mark icons on the permission check boxes become green square icons. What does that mean and how should I take care of it?

Please read documentation.

Thanks prikryl for answering my question.
So,Does Undefined Permissions mean permissions(undefined ones) of selected files/directories are different state? Is that correct?

Silvia1000 wrote:

So,Does Undefined Permissions mean permissions(undefined ones) of selected files/directories are different state? Is that correct?

Correct.

Thanks prikryl for answering my question.
I got it.