Recurring (every year): Owner's personal subscriptions, club/membership dues, above-market interest on owner loans, personal use of business assets (boat, plane).
One-time (this year only): Lawsuit settlements, partner buyouts, M&A/valuation fees, equipment failure or replacement, fire/flood/theft repairs, severance, achievement bonuses, recruiting fees for hard-to-fill roles, bad debt write-offs from a single failed customer, inventory write-downs, rebrand costs.
Enter each unusual item as its own line with the year it happened — buyers challenge one-time add-backs item by item, so each should stand alone.