You can set a limit to the number of cards added to a lane. If the limit is not set, any number of cards can be added to a lane by default.

1. Open the Visual Task Board.
2. Click on the lane header.
3. Select Set Lane Limit. Set Lane Limit for <name of the lane> window appears.
4. Enter the number you want to set for the specific lane. Leave blank, if you want set no limit to the lane.
5. Click Save.

Result

The number appears on the lane header. If the number of cards exceeds the set limit, the Red symbol appears on the lane header for all the board members.

If a card is moved to a lane with exceeded WIP lane limit, the error message appears on the top of the page. The member who moves a card to the lane with exceeded limit can view the error message.