Part 3 introduced tags narrowly, as context, what you need to do a task, and promised more later. Here’s the more.

A tag is just a piece of metadata that doesn’t have its own field, which means you can use them for almost anything, and over time you develop a personal vocabulary. Context is the obvious one: “computer,” “phone,” “errands,” so you can filter to what’s doable where you are. But I use tags for more than that. I keep a “waiting” tag for everything I’ve delegated or am expecting from someone. I tag tasks with people’s names (a short code, first initial plus a few letters of the last name) so I can surface everything tied to a given person, useful both for follow-ups and for “things to raise with Sam next time we talk.” Two more I lean on constantly. I keep an “off-hours” tag for tasks I don’t want surfacing during the workday, cleaning the gutters shouldn’t interrupt a work morning, so my Work filter is set to exclude anything tagged “off-hours,” and those tasks simply don’t appear until I’m off the clock. And I have an “agenda” tag, which I use together with a person or team name to do something a little different: a task tagged this way deliberately does not surface as a suggested next action. It stays out of my ranked list entirely. But when I have a meeting with that person, I pull up the filter for their name, and there it is, reminding me to raise it. It’s a task whose whole job is to appear at the right conversation, not to compete for my working time. Some people borrow the old GTD convention of a leading symbol to keep kinds of tags visually distinct, “@home” for locations, a different prefix for people, and so on.

I’m not prescribing any of this. The point is only that tags are a facet you grow into. Start with context, because that’s the one with an immediate payoff, and add others when you feel the need, not before. A tag you invented but never filtered by is just clutter. Let your real friction tell you which tags to create.