You can cancel an action you just performed by right clicking on your document's background and selecting "Cancel", or by pressing "ctrl-z" on your keyboard (cmd-z on mac).

You can as well cancel several actions in chronological order, there is no limitation regarding how many actions you can cancel but the actions history is emptied every time the page is refreshed.

How it works with collaborative work

When several persons are working on the same document, it can happen that another user edit an item parameter wich is concerned by the action you want to cancel. For exemple, you edit a post-it color and your teammate edit it as well, in that case you can no longer cancel your action in order not to cancel your teammate work. The following message is displayed :

This action is no longer available to cancel but you can cancel previous actions with ctrl-z.

In the case of cancellation of group modifications, for exemple if you edit the color of several post-its at once and another user edit the color of one post-it of this group, then if you cancel your action all post-its go back to their inital color except the one edited by your teammate. The following message is displayed :

If an action is in the process of being canceled, a loading feedback is displayed, you can no longer cancel other actions as long as this one is not over (as long as the feedback is displayed).