In gradebook settings under user settings option "Show hidden items:" is an option called "Show hidden". Which should according to the documentation show hidden grade items in gradebook. With this i understand that if an activity is set hidden on Course frontpage then the grade for the activity should be visible to the student in gradebook.
Unfortunately this setting has no effect.. I took a look at the code and saw the definition:
"define("GRADE_REPORT_USER_SHOW_HIDDEN", 2);" around line 33 which is ok.
But this is nowhere used in the grade/report/user/lib.php if or other statements. Other 2 options are used in statements.
It seems to me that this option is useless at the moment.. Can someone correct me? Is this a bug?