Brendan,
I have had a bit more of a play and have had some success. Just have to work out the order of Synonym over Child item over Sibling item. Maybe a bit of clarification would help there. I will have a go at importing some controlled vocab taxonomies.
The Structured Keywords is a hierarchical tree structure. So there are parent items and child items.
Lets say you have this:
animals
livestock
pets
wildlife
Animals is a parent item, and livestock, pets, and wildlife are children of animals. Livestock, pets, and wildlife are all siblings of each other.
So when you right-click on an item you can choose to create a child item (an item that belongs to it as a child to a parent) or you can create a sibling (another item at the same level.) With the above tree, if you right-clicked on animals, you could create a child item (which would be located with livestock, pets, and wildlife), or you could create a sibling item (which would be located at the same level as animals), or you could create a synonym for animals (which would be a child of animals but would be a word that means the same thing as animals.)
A synonym is a term that is a child item but is just another word that means the same thing as its parent but you have deemed it to be useful as a term to broaden the likelihood that someone searching for keywords would find what they're looking for.
For instance you could have the following
animals
pets
cat
Synonyms for cat could be: feline, kitty, pussy cat. You would make these terms synonyms of cat.
HTH,
-Kirk
