I haven't been able to find it yet, but I hope some others here will recall this...
There is a Sutta wherein the Buddha notes that while some declare their attainment by saying something such as "I have attained it", others would come to the Buddha, say a phrase of Dhamma, and depart - and that was their declaration. The Buddha, as I recall, seemed to prefer this latter approach, somewhat chiding the more overt declarers.
It's in the Majjhima Nikaya somewhere I think, but it might be a hidden prose piece somewhere in the Samyutta... anyway, I'm fairly certain it isn't online, but the overall tenor of the Sutta pretty much puts the kibosh on those who would go around saying "I am attainment X, I am attainment Y".
(The one I am trying to recall is not the Sunakkhatta Sutta, nor is it the Chabbisodhana Sutta, though both of those pertain to this topic.)