Glossary entry (derived from question below)
French term or phrase:
Numéro de décor
English translation:
pattern / décor / motif number
French term
United Kingdom
LAWYER-LINGUIST, ACCREDITED INTERPRETER
Native in: English (Variant: British)
Works in: French to English, Dutch to English, German to English, and 18 more.
Numéro de décor
Le numéro de décor
| 4 +3 | pattern / décor / motif number |
Bourth
|
| 4 | overlay number |
Adrian MM.
|
Proposed translations
pattern / décor / motif number
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Note added at 1 hr (2023-09-29 15:15:14 GMT)
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Note added at 1 hr (2023-09-29 15:15:56 GMT)
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Don't look too long at the picture below if you want to preserve your eyesight.
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Note added at 6 hrs (2023-09-29 20:08:14 GMT)
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Above, not below.
Austria
Retd.T&I, Barrister & Austro-Advokat
Native in: English (Variants: Scottish, British) 
Works in: Spanish to English, English to Spanish, French to English, and 5 more.
overlay number
Memory trigger: 'overlay tiling' from a relative's tiling business in South / Souf' London
IATE: en sheathing COM overlay COM fr panneau de doublage COM doublure COM revêtement
Chipboard Underfloor Heating *Overlay Boards* -> Overlaying protects the flooring. This acts as a cushion over the original tiles, which improves the overall durability of your flooring
http://www2.proz.com/kudoz/french-to-english/textiles-clothing-fashion/2302162-décor.html
http://www2.proz.com/kudoz/french-to-english/linguistics/1000377-décor.html
Discussion
Two examples (and redacted) from Technical Approval & Opinion (cladding & overcladding using composite panels):