Uniform Title vs. Variant Form of  Title (Ma'amar, Kuntres, Sefer, etc.                
 
The use of a uniform title (in LC practice) is automatic for *droppable* "Sefer." This is the only situation in Hebrew cataloging where the uniform title is more or less automatic.
 
For all the other situations, we simply follow AACR 2 chapter 25: has the work been published before? do some editions include the use of "Kuntres" etc. while others do not?  Note that 25.3B 1) is likely to be applicable in the case of "Ma'amar" for medieval works, although not necessarily for modern works.
 
As 25.1A in AACR 2-rev notes, the purpose is to satisfy the principle of  collocation.

Paul Maher