New user (Property Manager) setting up support system for residential tenants reporting maintenance issues, have only 4 support staff members but will assign tickets to up to 20 sub-contractors, plumbers, electricians, handymen, all sorts of tradesmen. We do not want any of the contractors to know who the others are, at the moment the way we set it up each contractor was set up as a staff member in a group called contractors and each are a team leader in individual team set up specifically for each contractor, working well but each contractor can look at a full list of all staff members (other contractors).Any suggestions on alternative structure greatly appreciated.