I am not sure If the word denialist is new which it is you are unlikely to find a source calling an organization 100 or 150 years ago denialist You might find all the characteristics of what denialism is of course It depends on how you define denialism If we define it very narrowly we will only end up with 1 or 2 topics in the category of denialism which clearly is wrong given the similarities of human behavior in those one or two areas with those in other subjects I believe we should do what dictionaries do when they define a word we look at prominent sources like the New York Times the New York Review of Books the London Times the Economist the Wall Street Journal Academic journals scholarly writing popular novels etc to see how the word is used For a new word this determines its meaning until a family of dictionary editors codifies this set of meanings as a family of different definitions that are published in dictionaries Since we are not yet at the dictionary publication stage but at the earlier pre dictionary publication stage we have to do more of the hard work ourselves That is all It is clearly a common word in common usage at least in some subject areas One rarely hears the word AIDS denier although that is essentially what an AIDS denialist is parenthetically noting that in fact an AIDS denialist is really an HIV denialist properly speaking And I suspect the phrase Holocaust denier will fade from usage now that the new word denialist seems to be gaining popularity If one maintains that there are two separate groups denialists and deniers then why are there no AIDS deniers Why no HIV deniers Only denialists Seems a bit strange given that human behavior is not much different in all these cases only the topic changes The denying stays the same If putting someone in a denialism category constitutes libel then a very large number of publications worldwide have put themselves in legal jeopardy by publishing articles on AIDS denialists and other kinds of denialists Given that these publications have full time legal staff and large legal budgets and the people making these claims on Wikipedia are not lawyers or legal experts this claim seems dubious at best If we accept the gratuitous personal assertions of some that denialism is really a political movement that involves personal gain then creationists creation scientists and intelligent design promoters fall in this category If denialism is more like denial of the evidence then this is less obviously true since there is a dispute about the evidence in these cases If we define denialism as some here claim to only mean those that know they are lying about the truth then where does that leave the most common usage of the word in the phrase AIDS denialism It obviously can not mean lying knowingly in this case or probably in all cases I suggest that if one requires a publication to directly make the claim that X is a Y to put some article in a category then we would depopulate most of the categories on Wikipedia If Y has characteristics Y1 Y2 Y3 Y4 Yn from dictionary definitions or from common usage and this common usage is well understood and evident from publication in WP V and WP RS sources as defined above and if X has most if not all of the characteristics Y1 Y2 Y3 Yn then surely X can be put in the category Y For example suppose we define a new type of urban area called a Townlet being an area with a common administration within a radius of 5 kilometers and a permanent human population of 5000 10000 people Then one surely does not need a publication to state that Filllsberg is a Townlet to put Filllsberg meeting all the necessary criteria in the category Townlet I also vehemently deny the assertion that denialist is a singularly negative category and so should not be used If so we would get rid of a large number of categories such as pseudoscience Also as I have stated repeatedly transhumanists or secular humanists or aetheists might be viewed as denialists by some And might feel perfectly proud to proclaim themselves as denialists of some overwhelming belief or putative evidence For these reasons I think there is nothing wrong with having a category called denialist or denialism The membership of this category might be controversial depending on what we take as the definition of the word Any particular subject might or might not be put in that category given community consensus on the word s definition and on the individual case by case analysis of any particular topic subject or article