Removing a redundant tag from OSM wiki

The tag landuse=peat_cutting is used over 250 times in OSM, whereas landuse=quarry,resource=peat is used zero times. (In addition, there are about 70 instances of landuse=quarry,quarry:type=peat_cutting.) It would therefore be wrong and misleading to remove documentation about landuse=peat_cutting from the wiki.

Remember that the Wiki is not there to document what "could" be or what someone thinks would be the cleanest, safest, nicest way to tag something - the Wiki is there to document what is actually used.

Edit: Pieren has pointed out that my numbers above are wrong. Indeed, resource=peat does have over 400 uses. This does not however change the fact that landuse=peat_cutting should not be simply deleted.

Frederik already gave a good answer for that particular tagging scheme, but to answer the more general question:

Changing something in the wiki starts by gathering consensus. Consensus can be obtained by :

• Seeing that the tagging scheme is already widely used in the database (taginfo should be the first thing you check).
• Discussing things in the relevant wiki page's discussion tab, in the (tagging) mailing list, or on IRC
• Writing a proposal and getting it aproved
• Seeing it supported by various tools, especially the renderers and editors

Once the consensus is clear and the tagging scheme is being used in the wild, you can go ahead and edit the wiki.

On taginfo, we find 478 resource=peat (and one "resource=Peat")
On those, 477 are combined with "landuse=quarry"

The database is not consistent. But it is not a reason to have the same inconsistency on the wiki. You should initiate a discussion on the tagging mailing list. The result should be a consensus for one of the versions present in the database and the wiki enhanced with that consensus (explaining the different existing values and combinations but we recommand only one).