It turns out to be the lines making the ‘tree’ linking the Comments (which I don’t use, and would like not to see).
In v3.x, I made Comments column 6 (as in, zero to six) in the [Playlists] sections of skin.ini, and HideColumns=6 worked: no comments ‘tree lines’ in any column, but I could still use Expand comments on the rare occasions a file contained any.
In v4.x, no matter what I try as a value for HideColumns, it doesn’t work, and Comments gets merged with another column (e.g. Link, as reported; or even in Time, my column zero, if I make HideColumns=-1). Even giving the Comments column a size of zero doesn’t stop mAirList insisting on drawing those lines in a Playlist column somewhere.
Needless to say, this ruins my carefully-sized Playlist column layout.
So, this is now a question: in v4.x, how do I completely hide the Comments column and NOT show those lines?
Separate options make no sense. If you want expandable containers, you need the tree lines, because this is where the expand/collapse buttons will appear. If you don’t want expandable containers, there’s no point in displaying the lines, because they have no other function.