The Title Says all
I’ve also been wondering what a rejection is as well. I’m interested in seeing a response. 
I’m pretty sure magic drop uses a string rejection, here is a thread on it http://yoyoexpert.com/forums/index.php/topic,37930.0.html
I know the magic drop, but that doesn’t really explain what a “rejection” trick is… thanks for trying to help though… Im still looking for some help!!
a rejection is when the string is pushed out of the yoyo while its spinning. heres a good video explaining a basic rejection.
I’ve seen the trick in 3a but never in 1a
yeah, there is two strings in the yoyo gap and one is pushed out. I should have given my response more thought. ???
A real cool rejection from takahiro iizuka.
when the string cross, you can push the yoyo away, and that cause the string out with a loop.
Also see some great video from jayyo, i like these rejection whip so much!
I have heard it also described as when you use the spin of the yoyo to make the string some out of the gap. One example I this (I believe) is the dismount for gyroscopic flip Andre shows on his video.