By default, initiative milestones (or actions or activities) are listed in initiative cards by milestone number. Custom sorting allows you to quickly find a milestone using any column attribute, such as start date, status, or planning summary. Sorting can be done in descending and ascending order.
To sort your milestones by a particular column, simply click on the sort icon that appears as you hover over the column header, as illustrated in the animation below. The sort icon will be blue for the column by which data is currently sorted. Any sorting changes made to a card will persist across all cards and will be present the next time the card is opened.