Some of the UK dataset's catalog items appear to be missing Uniclass 2015 codes, and other data seems to include references to standard GB dataset naming conventions.
The UK dataset is based on Uniclass 2015, however, parts of the specification were not yet finalized when the dataset was released. Bentley Systems is actively working with the Uniclass 2015 specification organization to better clarify and understand the structure of the standard; e.g., naming conventions, attribute values, and proper level assignment, in order to help with the remaining work.
There is also some clean-up required where older (GB) Uniclass definitions still exist on certain objects (such as Spaces) and where the Family & Part names also require additional updates as well. Much of this is also reliant on the ongoing discussions regarding Uniclass 2015 to determine what, where and how things should be named. The plan at this time is to release an update to the UK dataset shortly after the ABD Ss6 Update 1 release, which is tentatively scheduled for early Q1, 2016.