Charmaine I've cheated and copied and pasted this from http://www.geni.com/projects/South-Africa-Profile-Guidelines/16231
A Master Profile is the standard, most comprehensive and accurate profile for a given person. Other profiles for the same person are secondary and should eventually be merged into the Master Profile.
Curators have the ability to designate profiles as Master Profiles. You may request a Curator MP your profiles in the following circumstances:
Types of Master Profiles.
Historically significant people. Famous living people may require a duplicate public profile of the private one.
Well sourced profiles where the researched data fields need to be protected. In this instance fields may be locked.
Profiles that are at high risk of being mis-merged (including duplications due to adoption).
Where fields are locked, an explanatory Curator note will be added.
Locked fields should be filled in correctly according to Geni & SA Profile Guidelines.
If you would like to edit a locked field, please contact the Curator of the profile.
Defer to the Master Profile in Data Conflict Resolutions.
For more info on MPs please see: http://wiki.geni.com/index.php/Master_Profile