Was hoping you where off line cause I knew you have the answer!!
CSRN is controlled slow release nitrogen . EXAMPLE IS ?? somebody besides RIC
HWIN is hot water insoluble nitrogen example was uf, or nitroform (urea formaldehyde)sp.?
Now how long for HWIN in uf to release and the mechanism for releasing? Keep quite for awhile RIC.
Timothy J Murphy Specializing in Quality Turf
Bs in Plant and Soil Science
Almost 40 yrs exp., 20 as GC superintendent
Primarly work with cool season turf