MAP versus MSRP
MSRP is a suggested retail price. MAP is a floor on advertised price that the brand tries to enforce through its reseller agreements. A seller can in theory sell below MAP in a private channel but may not advertise it. On a marketplace that line is blurry, because the listing price is the advertisement.
How it plays on Amazon
Amazon does not enforce a brand's MAP policy on its own. Brands police it through Brand Registry tools, reseller contracts and by controlling who is authorized to sell. Price erosion by unauthorized sellers also costs you the Buy Box logic and drags on DTC, as covered in the essay on why protecting DTC from Amazon destroys both.
The EU caveat
In the EU, fixing a minimum resale price is generally treated as resale price maintenance under competition law, and restrictions on advertised prices can be viewed the same way. A MAP programme that works in the US may create legal exposure in Germany, France or Spain. Brands operating in Europe should take advice and rely on selective distribution, authorized reseller rules and brand protection instead.