According an update posted on the Study in the States website blog:
SEVP Policy Guidance S1.2 clarifies the acceptable additional evidence requirements for schools that do not meet the following criteria:
Owned and operated as a public school or school system by the United States, a state or a political subdivision thereof, and confers upon its graduates recognized bachelor’s, master’s, doctorate, professional or divinity degrees.
Accredited by a nationally recognized accrediting body and confers upon its graduates recognized bachelor’s, master’s, doctorate, professional or divinity degrees.
A secondary school operated by or as part of a postsecondary school that is a public educational institution or is accredited.
Here’s a link to the Final Guidance document:
