With logging turned on, all properties are recorded in the generated log file. In some cases, you may not want people to see a value. When this is the case use the MsiHiddenProperties Property. The MsiHiddenProperties property may be used to prevent the installer from displaying passwords or other confidential information in the log file. To prevent a property from being written into the log file, set the value of the MsiHiddenProperties property to the name of the property you wish to hide. You may hide multiple properties by specifying a string of property names delimited by semicolons (;).
Available with Windows Installer version 2.0 and later.