"Open admission" means that anyone who meets basic criteria, such as a high school diploma or equivalent, can be admitted to a school or program without any additional requirements or restrictions. Full definition
All shelter pets have a rough time of it, especially in open admission shelters where they're constantly at risk of being killed for space. (hypeorlando.com)
Black Cat Rescue exists because black cats often do not survive being surrendered to open admission animal shelters. (blackcatrescue.com)
At our large open admission shelter, which I've been at for more than a dozen years, we have never, ever seen this to be a problem. (aspcapro.org)