Does ドカンリイ (dokanrii) mean something?
https://www.deviantart.com/sonarpos/art/style-357-374585132. It's a photoshop filetype. I tried google translate, but it simply transliterated it.
I am a Japanese. There is not Japanese ドカンリイ probably think that is a coined word.
It's probably not a proper word, though maybe it's a username or something like that. ドカン is a sound effect that you can find in comics, but リイ is a bit strange in katakana because you would usually write a long vowel with a ー, so it would be リー.
They seem to use that word for quite a few of their styles with nothing really linking them visually together, similar to how they use the word "Style" without giving an official title, like a placeholder. 管理 kanri - management is the first thing that comes to mind, but the "do"? That last イ really throws me off as well. A name is most likely.