250 Most courts have concluded that, in addition to the aforementioned prerequisites enumerated in Federal Rule of Civil Procedure 23(a)-(b), a plaintiff seeking to certify a class action must also show that the membership of the proposed class is "ascertainable." 251 Although not articulated in Rule 23 explicitly, courts have concluded that Rule 23 implicitly requires the named plaintiff to prove that members of the proposed class are "ascertainable." 252 To satisfy this "ascertainability" requirement, "the members of the proposed class" must be "readily identifiable." 253 "The purpose of the ascertainability requirement is to avoid 'satellite litigation' over who is a member of the class and to 'properly enforce the preclusive effect of [a] final judgment' by clarifying 'who gets the benefit of any relief and who gets the burden of any loss.'" 254 Significantly, however, courts have disagreed regarding what a plaintiff must prove in order to satisfy the ascertainability requirement

First, metabolic alterations across different COPD subtypes remain poorly characterized, highlighting the need for subtype-specific investigations
"That's what happened here."
Penalties for Non-Compliance in Alcohol Shipping If you are caught attempting to ship alcohol through USPS, you could be fined, and possibly even spend time in jail
Glover M, Shepherd R, Selket K, Paramanathen SK