Eurocode 1 Part 1-1 (UK National Annex) Live Load Reduction

It is recommended that, in order to get the appropriate factors, you draw:

Domestic, residential, and office (Category A and B) loads on a Live (Reducible) layer
Assembly (Category C and D) loads on a Live (Unreducible) layer
Car park loads (Category F) on a Live (Parking) layer
Storage loads(Category E) on a Live (Storage) layer.
Roof loads (Category H) on a Live (Roof) layer

Note: Live load reduction will conservatively not be considered on Assembly loads in Category C and D. However it is necessary to assign the loads to the Live (Unreducible) type to get the appropriate factors in the load combinations.