The WHFS register is a central storage of links to important files and folders. Use this for 'where is my site? where is the project overview?' questions which can have only one valid answer per server (ie, where you would otherwise have to hardcode sitenames and folderpaths)
The register is not intended for objects that are unique per site - setting a contenttype on the site's root folder should suffice for that.
The WHFS register has been added in WebHare 4.13
USING THE REGISTER
Add a <registerslot> to your moduledefinition's publisher section
Instead of tid and descriptiontid, you can use title and description attributes with plain texts. The initialvalue attribute is optional - if used, this value will be looked up and set on first use.
To use the API, use LookupInWHFSRegister with the name of your slot, eg
LookupInWHFSRegister will never return 0, but will throw and explain which slot was not yet configured in its exception. It may, however, return ids of deleted objects..