How do hierarchical keywords in Lightroom actually work?

Question

I thought I understood how this worked, but I've just proven myself wrong. Imagine the following keyword hierarchy fragment:

- Locations
  - Europe
    - scotland
      - inner hebrides
        - isle of skye

My upper-case tags are "meta-tags" which are set to be excluded from export, but everything below Europe should be included. To me, the most sensible way for this to work, is that when I add isle of skye to a photograph, it automatically gets tagged with the ancestor tags. This doesn't happen. Is it possible, or have I fundamentally misunderstood the way this is meant to work?

Answer 1

The inherited ancestor keywords are second-class citizens compared to the keywords you explicitly apply. The ancestors won't show up as checked boxes in the Keyword List, for example. Instead, the ancestor keywords will be applied at export. There are (at least) two ways to verify that this is the case:

1. Export the photograph. For example, if you publish to Flickr, you should see the ancestor keywords in the photo's tags on Flickr.
2. In the Library module, in the Keywording pane, change the Keyword Tags drop-down to Will Export. This will show you both the keywords that you applied, plus the ancestor keywords that will export with them.

Answer 2

I think you understood but forgot a step.

When creating the keyword, you need to select "export containing keywords". When exporting, you need to select "Write Keywords as Lightroom Hierarchy".

Answer 3

Somewhat off-topic, but with Lightroom 4 and it's reverse geo-encoding, I'd encourage you to fill in the proper IPTC location fields: country, state, town, sublocation (or whatever their names are). These are all searchable in meta (just like keywords) and being in separate fields they are effectively in a hierarchy.