Has been posted before and probably the biggest annoyance in the game which is probably easily solved as frags are indicated already.
One previous closed topic on this subject I’ve found: Show hard mode missions in the “Find In” list for gear
Why do I think it’s important? Mainly due to the infrequent drop rate in the normal mode. So after the daily quest for normal I tend to focus on hard mode that has a better drop rate although at a higher cost.