A card-carrying effective altruist is one who does things that are endorsed by most effective altruists—e.g. donating to the against malaria foundation, working in an effective careers, perhaps going to EA meetups.
This doesn’t differentiate between:
the person is endorsed by members of the effective altruism community as it exists in real life
the person endorses the effective altruism community in turn
This doesn’t differentiate between:
the person is endorsed by members of the effective altruism community as it exists in real life
the person endorses the effective altruism community in turn
You can have one without the other.