There are many different combinations in which Champagne grapes can be grown and made into the sparkling wine. How this happens affects what is put on a Champagne bottle label. Here is an explanation of what the letters you see on the bottles mean.
NM – Négociant-Manipulant – This appears on the label of large Champagne houses who buy their grapes from a wide variety of other growers then make the Champagne under their own brand.
RM – Récoltant-Manipulant – This is a Champagne which is both grown and made by the same producer, known as a Grower Champagne.
CM – Coopérative-Manipulant – This is on the label when a group of small growers blend their grapes collectively and make a sparkling wine under one or more brands. They will usually be involved in the wine-making too.
RC – Récoltant-Coopérateur – This is when a grower provides grapes to a Coopérative- Manipulant and they make the wine on the grower’s behalf, under the grower’s own brand but without their involvement.
SR – Sociéte des Récoltants – When a small number of growers get together and share the same winery but make their own labels. This differs from a Coopérative-Manipulant because the growers keep their grapes separate, make their own brand, and are directly involved in the winemaking process.
ND – Negociant Distributeur – A company selling Champagne it did not make.
MA – Marque d’ Acheteur – A brand name owned by the purchaser, such as a restaurant, supermarket or wine merchant.