Hello slowly! Here is an answer to your question. The cusp is the point at which a new astrological sign begins. So, basically when one is born on the cusp, they are referring to be born at the beginning or the ending of an astrological sign. As in this case, Libra-Scorpio. This is at the end of a sign, which is Libra.
Now, I have many resources that state that the dates for a Libra-Scorpio cusp is from October 18th to the 22nd. On the 23rd of October one is now a Scorpio in the rawest form. I have not seen Oct 18th-the 28th! That is way to late. Could you site your source so I can see it?
Characteristics of a Libra-Scorpio cusp individual are: A libra with scorpio tendencies. They have strong magnetic personal charm and usually try to maneuver situations so that they are the ones that are controlling or directing any given situation. They know how to work hard, apply themselves to the whole ideal to achieve a goal and are skillful when dealing with people. Also, their sensuality is very attractive to others, even though typically they are unaware of this. At times they can be impatient, quick tempered, but don't really like arguements and are willing to keep the peace. Finally, they have a captivating social nature, however punctuality is not one of their strong points.
I hope this answered your question?
peace, love and light.
Lady bastet