One useful thing about this index is that it includes "both sides" of a citation. That is, if as in 1En 1.1 a citation is noted for PsSol 4.9, at PsSol 4.9 you will find a corresponding citation for 1En 1.1. This may or may not have been the case in the original OTP marginal notations. Imade certain to make it so in this index.
More introductory details can be found on the last page of the file (p. 178!). Looks extremely useful.
(Via Jim West's Biblical Theology blog.)