You might think that there is only one account with a "." (dot) on the username (https://namemc.com/profile/354b/.Flow), but there's actually another one. The reason because most of you didn't know about this, is because you can't check if the account exists or not (on NameMC) since it assumes it's a server (letter+dot+letter), formerly you could check at (http://mcskinsearch.com/skin/T.Pinkelmann) but somehow they've changed the website and it doesn't let you access to it anymore.
I was quite surprised when I realized this months ago on mcforums (http://www.minecraftforum.net/forums/archive/mojang-account-minecraft-net/1944135-2-letter-number-mine-craft-lnames) i'd love to see the profile on namemc tho
For some reason, T.Pinkelmann doesn't show up on NameMC, either it doesn't exist, or it got deleted, but. Flow isn't the only one either; there is also Mr.Lol and Mr.Denis and possibly others but I am too lazy to find more.
(Thanks Grammarly for helping me fix the grammar issues, damn this does its thing excellent!)
@Poor It doesn't show up because namemc assumes it's a server (letter+dot+letter)