In the clean/trad style, a route is climbed without fixed belay points. Pitons are not allowed. This means that the climber places all pieces of gear used as protection (and also to build an anchor if needed) and removes them completely after the ascent. In this case, the natural characteristics of the rock are used as placements for trad gear, like stoppers, cams or slings. Recognizing placements and correctly placing trad gear requires a lot of experience, which can only be acquired with a lot of practice. Clean/trad climbing follows the ethic of leaving no traces and especially not damaging the rock, and is practiced, for example, in the Elbsandsteingebirge (GER), on many granite walls in Chamonix (FR) and in Yosemite Valley (USA). Nowadays, there are also often routes that have bolted anchors, so the climber only has to place the intermediate protection.
In general, clean/trad can be defined more as a type of climbing than as a style of climbing, since a clean/trad route can be climbed onsight, flash, redpoint, pinkpoint, as well as on toprope. In the meantime, another climbing style has been established especially for clean/trad climbing, the so-called ‘greenpointing’ where a route is climbed clean/trad even though it is protected with bolts. But it only counts if you climb the route on lead. Now, you may ask yourself why you do that when there are bolts. However, there are many reasons for this. For example, there are climbers who simply like to fiddle around with friends and stoppers, or beginners who want to approach trad climbing slowly and would like to have bolts as a backup. In addition, there may be climbers who are in an area with routes far below their own difficulty level and where independently placing protection adds a certain pizzazz.