Who are the International players

Playing a USA team that only allows 8 international players to be picked for Registration. It says I have 8 picked already but I only see 6 with the international “I” tag next to there name, I have 15 where they have a different Nation of Birth Flag and 12 of them are picked for registration. I am totally confused on which players are considered International players. Is there a way I can see which players they say are the international players? I ask because I have a new better international player coming under contract and I need to make room for him for the next registration date.  Any guidance would be of great help.