Minimum unitholding requirement enforces locked in, unencumbered holdings by SM REIT investment managers over phased post listing periods. Tiered minimum unitholding obligations require the investment manager of an SM REIT to maintain specified percentages of total outstanding units at all times in defined multi year intervals from the date of listing, with higher initial thresholds where schemes opt for leverage and any excess holding retained for an additional year. Units relied upon to meet these obligations must be unencumbered and locked in, and units issued against pre chapter swap arrangements are excluded from the denominator for calculation purposes.