The following System Options (accessed by navigating to Tools > System Options and then clicking the System Options button) apply to the Deeds functionality:
Deed Auto Unique Number (under Auto Numbering) - allows the system to automatically generate each new deed or be entered manually
Deed Item Allocated Percentage - Decimal Places (under Estates) - sets the precision of the Allocated Percentage Area field to the number of decimal places set in this setting
Enforce Site Deed Item (under Estates) - requires that at least one site must be linked as a deed item when set to 'True'