The single overriding aim of our search it to find the SINGLE company a customer is looking for or at least get it to be in the first 10 matches. It is NOT to trawl through our complete company (or officer) names and numbers, there are other products for that.
All that said, the search is an 'OR' and a 'AND' search, that searches indexes of the company name, company number, surname, forename, other names and postcode, with some analysis on other fields like dissolved dates to help with relevance.
Just looking at your example of 'The Donaldson Trust' , that company does not exist, so no exact match. If you tried for example 'DONALDSON TRUSTEE LIMITED' it is the first match as an exact match.
There is a bit more detail regarding our search facility on the following forum thread:-