Location of Knowledge Base

Could someone point me in the direction of the current location of the Knowledge Base? I am interested in learning about Extra Content Containers.
See attached screenshot.

The RealMac RapidWeaver KB is here:
https://help.realmacsoftware.com

Don’t think you will find anything on Extra Content Stacks, as that’s not a RealMac (or Stacks) product.

Here are some resources for Extra Content:
http://foss.seydoggy.com/?p=ExtraContent
https://stacks4stacks.com/extracontentplus/

@mokane99 As I said by email a few days ago, if you are trying to access the ThemeFlood Knowledgebase for articles like ExtraContent, simply go to any one of the theme product pages.

Look under ā€˜support links’ in the sidebar and click the link marked ā€˜ThemeFlood Knowledgebase’.

For example, if you want ExtraContent, here it is:

Like @teefers says, you are unlikly to find much information on topics like ExtraContent in the Realmac Software knowledgebase or RapidWeaver user guide, because ExtraContent is not a part of the theme API. This is a third-party developer collaboration.