items also possible only much work.
the question is for what the player get the flag. as example if the player must make a quest that the flag get set it work.
and another question is how much work you are willing to spend in it
you can make a simple npc that check flag and trade items like it work in mir3 (zentaur or hasekura server)
you create a ring and call it Ring(old) and change the ring to a normal annicount that you can store hold in bag or drop or trade but not put on. than you have also a second ring in your db that you can wear. than you need only put the (old) ring in drop files and create the npc that change old to usefull. that npc can check flag and say as example
sorry you have not done that quest i can not make the old ring usefull without the questitem or the knowledge you done it.
so you see you need than for each item a flag or for a special groups of items a flag or you make it with txt file "addnamelist checknamelist delnamelist" dunno if it work in mir2 but it work in woool and mir3 and you must create much items (old) and edit much dropfiles.
so you see the question is only how much work you will spend or how the people get the flags and for how much items
