It was this thread at the PD-dev list:

[PD-dev] cyclone and uppercase
http://lists.puredata.info/pipermail/pd-dev/2009-03/013146.html

Fred Jan

On 2015-03-05 06:18 PM, Alexandre Torres Porres wrote:
> Hi, I have a question about upper case letters in the begining of some
> objects like [Uzi] and [Scope~] in cyclone. Why is that? In Pd it does
> make a difference by the way, not in Max.
>
> Anyway, if one would change that, old patches would need to be updated
> as well, which is a bummer, but even so I think it's preferable not to
> deal with knowing which objects need the upper case or not, and for no
> apparent particular reason. One way or another, I wonder why it
> happened, anyone?
>
> cheers