These pieces are often referred to as black books” or “black” papers. 
“The black books were originally put into a box and sealed up in a back room. It was later discovered they were not sealed and were quite easy to open. Eventually these black books got out of the back room and into circulation and now researchers, who had access to the black books, could read through it and find scientific papers that corroborated or opposed those ideas.” 
For example, this is a document dated September of 2004 discussing the possibility that a UFO crashed in the Soweto countryside in South Africa in 1972. 
The document indicates a desire to include that in further publications such as a full-length book. “There are at least two full-length books that may well contain details of the event and that are still available.” 
One of the main reasons for the widespread use of black books is the idea that the information in a black book can be more widely disseminated than in a peer-reviewed scientific article. 
And, it seems to be working, as the UFOTC has seen an influx of new recruits after the disclosure of a number of black books over the past few months. Some have said that the disclosure of the black books is the main factor that has pushed the UFO movement into the mainstream of knowledge. 
As time goes on and our knowledge expands, perhaps black books will lose more of their utility as an academic discussion tool. At the time that the document was written, the existence of black books were still somewhat controversial within the academic world, and, as we know, the scientific literature was not yet as well known within the general public as it is today.
But, is there a difference between black books and black box material? What about a “black hole?” The concept of a black box is a rather technical one. When discussing what is contained within a black box it needs to be emphasized that there is the possibility of a leak and disclosure. When we speak of black books or black boxes, it’s not just that something is in the box. So, it’s a box containing something. 
When we look at the question of the black books itself, we have to think about those “black” papers: they are documents that do not originate from the original source. Those who have access to the documents in question are capable of putting together the facts by their methods as they see fit and putting them into context.
So, there’s no question that there could be a leak, and the documents themselves could possibly not be entirely true.
But, these black books should not be called scientific papers, just because they are so difficult to read. The scientific process requires that there be a lot of work done beforehand to determine the true nature of the facts. With black books, the initial information is usually just that – initial information – and all the information from this point forward does not have to be researched by scientists in order to come to an assessment about the validity of the information contained within.
As we’ve seen, one of the primary sources of documentation within the UFO movement right now has to be a large number of anonymous sources. It’s possible that some of these anonymous sources were involved in the writing of the black books. Even if some of the black books were simply written by
These pieces are often referred to as black books” or “black” papers.