At that time of the year, graduate schools in the United States are notifying applicants that they have been placed on a wait list.
I read this email sent by a top-ranked University's computer science department:
Our Committee on Admissions has asked me to tell you that we have placed your application (along with about 50 others) on a "Wait List" for any openings which may occur. […] in the past several years we were only able to offer admission to only a few students who were on the "Wait List".
As a reference point, this University's department accept around 100 student every year.
What is the point of having a waitlist of size 50 while intending to eventually offer a position to only a few applicants?