Organize

The third of GTD’s five steps: putting each clarified thing where it belongs — a next action on its context list, a multi-step outcome on the projects list, a dated commitment on the calendar, a delegated one under waiting for, an idea under someday/maybe, and information in reference — so that the right list shows the right things at the right time

Organizing is filing by when you need to see it again, not by topic. That is why the lists are what they are: contexts for what you can do now, the calendar for what must happen on a day, waiting-for for what someone else owes, the tickler for what you do not want to see until a date. PARA is the reference half of this step applied to a whole knowledge base.