[v8i] Level Manager with Library Levels - Update from Library Hover Tip = Snap?

We have a level library DGNLIB and I was in a file and noticed the Dot in the Modified (blue delta character) column, so I decided to use the right click: update from library command.

A few levels remained with a Dot. Some, when I hovered over, said Plot, so I toggled their plot column since apparently update from library does not affect Plot. But some still retained their Dot. So now, when I hover over them, they say Snap.

What does that mean? There is no Snap property that I am aware of.