CamelCasing a Constant: Acceptable Practice?

[kyonides]

Well, since I've been searching for pure ruby scripts and I joined #ruby-lang channel at freenode.net I think, the comments I can now recall make me think that in Ruby there are many "flavors" when talking about how to deal with syntax in a few aspects but one thing I'd like to mention is that Constants are supposed to be written in CamelCase or be capitalized only (Capitalized) if you're using the Constant as a class or module name. For any other purposes they're supposed to be written all in uppercase. They say it'd distinguish the use or purpose those Constants have...

One thing I only found in RGSS(2) but never in pure Ruby was the underscore. Really, I've downloaded RB files, installed Ruby Gems, etc. and I've never seen a single Constant written with an underscore in between (especially if used as a class or module name). There are some basic programming books based on Ruby saying you should never use underscore, others just ignore that the underscore even exist... except for naming methods with def end... That makes me think that Constants like This_Is_A_Constant can only be found if the scripter is someone who usually codes or works in C or any of its variants.