There are two ways to create a fact set. One way is to clone an existing fact set, which you can do in the Fact Sets Dialog. You can also create a fact set by creating a new fact definition, and giving it the name of your new fact set. Thereafter, you can add more fact definitions to that fact set by simply creating more new fact definitions and giving them all the same new fact set name. You can even move existing fact definitions to the new fact set from other fact sets, by changing their fact set name to be that of the new fact set. The only exception to this is that you cannot move fact definitions into, or out of, the standard fact set (called 'Standard').
There is no limit to the number of fact sets that you can have installed at any one time, or to the number of fact definitions within any given fact set.
There are two ways to delete a fact set. Custom fact sets can be deleted in the Fact Sets Dialog.The alternative is to simply delete all the fact definitions that belong to that set, or move them to other fact sets. You cannot delete the standard fact set. You can hide standard fact definitions but you cannot delete them.
See Work with Fact Sets for more information about fact sets, and how to create, delete or modify fact definitions. See also and Importing and Exporting Fact Sets.