I was battling somebod. I hand my houndoom (low on health) and they had an alakazam. They used some move on me, and it said that houndoom was identified. then I used dark pulse, and they lived with on HP thanks to a focus sash. then alakazam used psychic and it hit my houndoom! I thought dark types were immune to psychic attacks.
The move that "identified" houndoom must have been the move miracle eye. It neutralizes your evasiveness, but more intrestingly, if used on a dark type pokemon, it eliminates their psychic immunity, making them open to attack. It is just like the move foresight. look at this for more info.
When a pokemon is "identified" it basically means that you have lost your resistance.