As Andre Engels already made clear, neither the ISO code nor the SIL list can be taken for granted in all cases, regarding what we actually look for in their lists. He gave good examples, and so did Tim Starling. In fact, my opinion on this topic is, that we should use both the ISO and the SIL when we’re unsure again whether to allow a certain language or not. What were the 3 artificial languages on Ethnologue again? Esperanto, Interlingua and... Europanto or something, I don’t remember. Well, we have a Volapük Wikipedia, to which I and some others even contribute, from time to time. Volapük is not included in the SIL index but in the ISO codes. That’d be a pro. Thus, if the language can be found in either the ISO or the SIL list, it has a right to exist. But we should still consider each new language if there are enough contributors for it. Maybe 3 or 5 could be enough. That would speak for Klingon as well – there is an ISO code (tlh), there are more than just 3 or 5 contributors, and the vocabulary and grammar is large enough as well (a fact that in my opinion doesn’t really apply for Sindarin/Quenya, for example). I don’t know off-hand which other constructed languages could be found in the ISO codes (too lazy to look it up now ;)), but I doubt that there are more „fictional“ languages besides Klingon. And Toki Pona is wiki-fied already – it’d be unfair to remove it now, if it’s included in ISO/SIL or not. Okay, I think you understand my point. - André