[silentguy]

When you create a catalog, you can set prefix rules. For yes no columns in can choose 4 values there: "", "true", "false", "unspecified". Some testing showed the the empty string and unspecified are never applied, true means yes and false means no or unspecified. Why is this not handled like the normal search where no means no, yes means yes, false means no value given and true means value give ie yes or no. I would really like to be able to have a way to give a prefix for Yes and another for No, without having the no prefix also apply to the books where read is not set.
Sorry if this is already covered, but yes and no are not searchable in the forum and I'm only posting from my mobile phone which makes using it harder still :-P