HT = Hand Tucked Splice and Hidden Tuck Splice.
For hidden tuck splice (IWRC) use values in HT columns.
S = Swaged or Zinc Poured Socket
* These values only apply when the D/d ratio for HT slings is 10 or greater, and for MS and S slings is 20 or greater where:
D = Diameter of curvature around which the body of the sling is bent.