Top IPC subclasses
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1
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E04D
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5
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roof coveringssky-lightsguttersroof-working tools
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2
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E04B
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3
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General building constructions; walls, e.g. partitions; roofs; floors; ceilings; insulation or other protection of buildings
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3
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E04F
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2
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finishing work on buildings, e.g. stairs, floors
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4
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E04C
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1
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Structural elements; building materials
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5
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F24J
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1
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Production or use of heat not otherwise provided for
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6
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F25B
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1
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refrigeration machines, plants, or systemscombined heating and refrigeration systemsheat pump system
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