I always thought that books wrote RP Mk 2 with that dot to separate the prefix from the Mk letters That makes two of us speculating on editors reasons Regarding the Lynx page I was not referring to the RP 2 format which I have always found a fine shortening but to instances down the page where we see Mk 21A instead of Mk 21A You will see that Wikipedia WikiProject Aviation Style guide Naming British military aircraft takes the dot in Mk as acceptable but not preferred Likewise in this article we are discussing here I do think your last statement missed the point somewhat The article is about the names the prefixes and the numbers but not really about the formats WP should be consistent in that the page teaching the correct names this one should match the page teaching the recommended format that one On this one page here and on the matter of dots alone I believe that the formats should be used so as to set a consistent example for the reader never having it any other way but the chosen way I believe that we even have consensus on the preferred usage between dots and no dots The only real discrepancy I see is sometimes using Mk and sometimes Mk here when the former is discouraged and the article is not commenting on the alternate usage of dots no dots To put it shortly I should think that between Mk and Mk the article should adopt only one regardless of which one and I would add that both WP and I prefer the second one but this is beside the point Curiously enough by now I have departed from my main points when creating this section but I also see that we managed to pinpoint the issue where consensus and referencing can both be found