SpamSieve rule / SpamSieve C-Command account?

The Spam Sieve Help says,

Open Mail’s preferences and find the SpamSieve rule. Select the server mailbox that you want to use.

and the illustration shows a SpamSieve C-Command account.

My rules don’t have a SpamSieve Rule and I don’t see a SpamSieve C-Command account in the Rules preferences or the Accounts preferences.

Creating the SpamSieve rule is Step 3 of the setup. The account name mentioned there would be the name of one of your accounts, not “C-Command”.