Wait, is there a channel called #powder-games?

But seriously, #powder-forums = #powder-forum + s, it's easy for anyone to make a typo, go to the wrong channel and get confused.
Also, read this:

"Primary channel names, formatted with a single leading hash mark (#), are reserved for participating groups and organizations based on their legal or informal claim to the associated name or name prefix. For example, freenode has reserved and holds control of the freenode namespace. That means freenode has been granted control over channel #freenode, as well as any channel beginning with #freenode-.

Name claims can be appealed, at which point network staff will look for an appropriate resolution to the conflict. We may suggest informal solutions to promote compromise by the parties involved; but in the absence of such solutions, we'll give priority to groups in the following categories, listed in order from highest to lowest priority. Within each category, we'll give priority to the group with the longest documented use of the name. "

similar to #freenode and #freenode-*, #powder is a claimed/reserved namespace, which makes any channel starting with #powder- a part of it.
idk much about freenode channels, but I guess reading should help.

Edit: Another example, #wikipedia is a reserved channel which means #wikipedia-en is a part of it as well as #wikipedia-en-help and a lot more channels related to wikipedia.