Some big ones...
** Idealization/devaluation, which is seeing others as super perfect (on a pedestal) or terrible -- periodically switching from one to the other. Like d_h said, the "I love you!, I hate you!, Don't leave me!". I think they call it "splitting". It's a combination of "black and white thinking" along with abandonment issues.

**Issues are ongoing and pervasive (one's regular pattern of thoughts and interactions), as opposed to happening only during mood episodes.

** Chronic feelings of emptiness. And having a hard time feeling loved and worthwhile when alone -- without someone there to reassure. Damn. There is a name for that, but I can't remember it atm.

**There is a big tendency to do things that push people away, ironically most often with those one seeks to have love them. They say is comes with feelings like, "they're going to leave me anyway... everyone always does". It's almost like a test too...pushing boundaries...seeing how far they'll go to prove their love... "if you cared enough you'd...". The person on the other side would probably finish that sentence, "be able to read your mind.", because of receiving such mixed signals. Like.... saying, "leave me alone!", while actually wanting them to come to you.

**I think this one's based in abandonment issues and the difficulty feeling someone's love when they're not there. An observation... Say someone doesn't call back right away. The immediate thought is one of personal rejection. This tends to lead to calling many times over. Seeking reassurance is my guess (frantic efforts to avoid real and imagined abandonment). Also a tendency to "read between the lines" for negative meaning where none is intended by the other party (transient paranoia).

The page right here at PC is quite informative:
http://psychcentral.com/lib/2007/sym...lity-disorder/

There has been talk of renaming it to Emotional Regulation Disorder. Pretty apt, as there is a tendency to feel ruled by one's very intense emotions and feelings.

I don't have it , in fact it perplexes the hell out of me. But I've been reading up because I live on the other side of this. Now that I know what's going on, I better understand the behaviors. Before that, wow, was I confused.