According to Wikipedia, psychologist Theodore Millon identified four subtypes of borderline personality disorder (BPD). They are:

discouraged borderline--includes avoidant, depressive or dependent behaviors impulsive borderline--includes antisocial or approval-seeking behaviors petulant borderline--includes passive-aggressive behaviors self-destructive borderline--includes depressive or self-destructive behaviors

A person with BPD may have none, one, or more than one of these subtypes. I believe I fall under the discouraged and self-destructive subtypes.

Discouraged borderline

This is a person who believes that no matter what, they just can't win. Consequently, he or she may avoid people, believing they will not want to be around him/her. The other extreme is he or she may be overly dependent on other people, hoping to find some sense of self-worth from them. This person may also suffer from symptoms of depression.

This person is operating in an Abandoned Child mode. He or she believes that he or she is unworthy of love and affection. He or she believes no one will want anything to do with him/her, and behaves accordingly. This may include frantic efforts to avoid the end of or disturbance of any relationship, black-and-white thinking, or unstable sense of self.

Impulsive borderline

I've dealt with this kind of person before, and it's not a pleasant experience. This is what mental health professionals usually mean when they say "borderline". This type of person is in constant conflict with society. Bouts of violence are not uncommon. This person does not think before acting, and the result is chaos for everyone involved. This person may have antisocial personality disorder as a co-occurring diagnosis.

This person is operating in an Abandoned Child mode--a plea for attention, any attention--as well as an Angry Child mode. The Angry Child believes that other people deserve to be punished for his/her pain, and behaves accordingly. This type of person with BPD may have poor impulse control, abuse substances, or self-harm.

On the other extreme, he or she may seek approval at any cost. In a way this is just as damaging as bouts of self-injurious behavior. He or she may not care about himself/herself; it's all about what the other person thinks. This often results in extreme efforts to avoid disapproval and abandonment.

Petulant borderline

This is a passive-aggressive person. He or she will injure himself or herself--either physically or emotionally--in an attempt to get needs met. This person has an unstable sense of self, a frantic fear of abandonment, and inability to express his or her needs.

This person operates in an Angry Child mode. He or she is angry and will hurt friends and family as a result. He or she often does not recognize the anger--the world is the problem, not him/her. He or she does not know how to express his/her needs in a healthy way, so relationships seem to be a game of "If you really loved me" or "You should know what I want".

Self-destructive borderline

This is the popular cultural image of a person with BPD; "Goth" or "emo". This person often suffers from depression as a co-occurring diagnosis and is a self-injurer. Oftentimes, just these two criteria--emotional instability and self-injurious behavior--are enough to merit a diagnosis of BPD (in spite of the DSM-IV mandating a diagnosis of BPD if five of nine criteria are met). This is a person who feels that no one cares, and reacts by not caring about himself or herself.

This person operates in an Abandoned Child mode. Since he or she does not feel loved, he or she reacts in self-destructive ways in an attempt to feel something instead of nothing. He or she lives in terror of abandonment, is self-loathing, and has no idea who he or she is inside. Thoughts of self-injury--or actions--are a given in this type.

The good news about BPD

The good news is there is hope. BPD is treatable. However, it is useful to know if you fall into a subtype in order to better communicate with your mental health professional. You may not know where you fall, and you may not fall into one of those categories--that's okay. What's important is that you understand your diagnosis, in order to improve the outcome of treatment. There is hope--even if you feel like you're the worst insert-subtype in the history of psychiatry.