Tags describe what kind of thing something is. A thing can have as many as you like.
Tags nest
Put spices
under food, and clicking food
lists everything tagged with either. The number
next to a tag is how many things carry it.
Default home
A tag can have a default home: "spices live in the spice rack". A thing with that tag and no usual home of its own shows "Usually lives in" the spice rack on its page. It's a reminder, not a rule; nothing gets moved.
Attribute templates
What a thing with this tag usually has written down. A template on paint
of colour, finish, size:L
means every
tin of paint's page offers those three fields to fill in, so you don't have to
remember what to record. The part after a colon is the unit.
Templates are inherited: a template on diy applies
to paint things too, and the more specific tag wins if both
name the same field. A field stops being offered once the thing has it.
Where tags come from
Mostly by typing them when you stash or edit a thing: a name nobody has
used before becomes a new tag. This page is for arranging them — nesting
one under another, default homes, attribute templates. Suggest tags
on a
thing's page only ever offers tags you already have, which is what keeps
you from ending up with christmas, Xmas
and xmas-decorations. Reading a photo is the exception: it may propose a new
tag alongside the things it finds, and you see it before anything is
stashed.