When there are e.g. several parts to a published publication series and a user has plenty of other published works, it may be clearer to let a stacked presentation indicate that there several solutions more for a reader to select. In practice, this is done by adding a "#" character (without a space) after the group name in solutions' settings, followed by a number. Then, on the Profile tab of the user preferences, in the "Stackable groups" text field, the information specifying the stack is added, following the syntax "group name#snippet number#snippet name#snippet title". The last two are optional, but the group name and stack number must be included. If there is more than one stack, they are separated by a semicolon.
Clicking on a stack in a solution index will show the solutions in that stack, arranged similarly, without changing the web address.
If you later decide that you don't want to use certain stack, it is not necessary to edit group names in the settings of each solution as it is sufficient to remove the defined stack in the user settings. Any additions to the group names, such as "#1", will then simply remain unused.
One of the things that makes this experimental is that many browsers do not apply the antialiasing effect to images that have been rotated, which then looks rather coarse, especially the images containing text.