This release switches Nominatim to the ICU tokenizer introduced in the last year. After many months of testing and improving, we are now confident that it is ready for wider use. Next to the features already mentioned in the last release, the ICU tokenizer now also has a module for improved parsing of house numbers and postcodes. The new codes detects possible errors in the OSM source data and improves search for housenumbers and postcodes with spaces in them.
A more complete list of changes can be found in the Changelog.
Updating from 3.6.x to 4.0.x to the new release is straightforward. Please follow the instructions from the migration guide. Updating from older versions is possible but not recommended. A complete reimport is required for using the ICU tokenizer.
Please note that this release drops support for PostgreSQL 9.6.