Rough-in
From Toiletpedia
When talking toilets, the rough-in is the distance from the wall behind the toilet to the center of the outlet pipe where the waste leaves the toilet. The most common distance is 12 inches, so most toilets have a "12-inch rough." In some circumstances, the outlet is closer to or further away from the wall. For those cases, toilets are available with a 10-inch rough or 14-inch rough.
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