I read my privates messages on board the normandy and got 2 messages that told me to go visit 2 persons in the Citadel (Thane in Hospital and some guy in a bar).
Now I 'm back in the citadel and can't find referring journal entries.
Are those minor tasks visible somewhere? They don't show in the journal.
I am playing the ps3 version.
Unfortunately, there is no list of minor tasks, where someone asked you to meet them on the Citadel.
However, whenever you can talk to someone on the Citadel, their name will show up on the Citadel map for the section that they're in. Whenever I visit the Citadel, I make sure to go through all of the sections of the map and make sure that I talk to everyone listed so that I don't miss anything.
There are no entries for some minor stuff in your journal. You'll have to keep track of those the old fashioned way, either remembering them or writing them down. People that you're supposed to meet on the Citadel are one of the cases where there is almost never a journal entry, just remember the location from the mail and go there.
