This command allows a block to break across the columns within a frame.

When this command is specified within a block that is nested within a parent slim table of <?tbovflow=3>, or within a parent multi column block, this will span across the parent’s columns If the columns being spanned are also being balanced this will delineate the balance regions. If nested within a block that is being balanced, even if it’s not the direct parent, this will cause the existing content to be balanced first. This essentially causes a new row within the block that is being balanced.

Any content that follows a block that breaks across columns will have the column top margin applied instead of the normal top margin.