IPplan IP address management system

Hi,

Can someone please explain the term mentioned "Active polled (D/W/M/Y)"

I'm unable to understand how this terms are changed always in front of the IP's.

I scanned a subnet yesterday at that the the Status in front of all the IP's were shown as "D"

And today when I'm seeing that subnet then there's "W" in front of all the IP's.

I'm unable to understand the Abbreviations (D/W/M/Y) and when It is changed, what does it indicate ??

Someone please explain....

Thanks,
Keyur