Preferences

The Host Object and i Project decorators can be enabled from Windows | Preferences | General | Appearance | Label Decorations:

There is a link to the 'Label Decoration' preferences on the related iSphere preferences page:

The available message file search options are:

Add library name to objects - Specifies whether or not the the name of the library that contains the object is added to the object decoration objects.
Add library and file name to source members - Specifies whether or not the qualified name of the parent file is added to the object decoration of source physical file members.
Add library and file name to data members - Specifies whether or not the qualified name of the parent file is added to the object decoration of data physical file members.