Hello i know from Witcher 2 when you walk up to an notice board and you see some quest there it auto add and says "new quest".
In Witcher 3 now i walked upto the notice board in first town i had one Wanted quest and some other quest there totally 6 of them. I pressed "E" button to take the letters but i cant see those letters in my inventory or under my Side quest. All i have under my side quest is Collect em all.

I think a lot of those notes are just for flavor. You can get some quests from the notice boards. I think the notice board icon is yellow when it has a quest.

Some are just notes, others are quests.

Thanks fellas :)!

If it's a quest or a monster contract you will see a seal on it, otherwise it's just a note.