What I mean is that when you go on the PC thingy in the Pokemon Center, you can put marks on your Pokemon (Little shapes like stars and circles) which appear in their summary. Is there any point to this?
They are for sorting & organizing Pokemon and serve no purpose other than that reason.
A marking tool was introduced in the Generation III games, with Lanette's Pokémon Storage System. This tool helps the player to organize their Pokémon within the boxes, but is not necessary for game play.
http://bulbapedia.bulbagarden.net/wiki/Pokémon_Storage_System#Markings
So to answer the question, no, they don't have any plot-necessary purpose.
The point of the Markers is to make the Pokemon unique to you. Then you can regognise your Pokemon trade. Apart from that there is no other reason for them. Hope this helps ^^
Only in the pc dose it serve a puporose
