Companies House has confirmed the appointment of Italian executive Caboni, 61, who worked alongside Massimo Cellino during his time as owner of Cagliari, was filed on January 21.
Andrew Umbers was appointed to the Leeds board earlier this month and was last week named as chairman when Cellino was forced to step down after losing his appeal against the Football League's decision to ban him.
The League disqualified Cellino from being owner or being a "relevant person" with the club after he failed its 'owners and directors' test due to a conviction in Italy for tax evasion.
Cellino has confirmed he will return as club president when his ban expires on April 10.
Eleanora Sport director Daniel Arty and Cellino's sons Edoardo and Ercole are other directors, while Salem Patel and Jinesh Patel are also on the board, representing Gulf Finance House Capital, who own 25% of the club.