Doitsu, thanks again for the suggestions. I'm really clutching at straws so appreciate your ideas.
I've tried a version of what you suggested.
Here's the file I created:
<idx:entry name="word" scriptable="yes">
<idx:orth value="頭 【あたま】">
The index seems to be broken. When I do a search (in the dictionary) nothing comes out, just a blank page. The entry itself can be seen if you read the dictionary though.
The documentation has this to say for the value attribute:
Use the value attribute to include text for the label in the entry that you do not want to display in the OEB flow
I don't understand what that means very much because the documentation fails to define the terms they use. For example what's a 'label', what's an 'entry', and what is the 'OEB flow'?