(The WLC is the text of the WHM, but the WHM includes additional information, namely the dictionary “lemma” and morphological analysis or “parsing” for each word.)
Compared to the previous release (WHM 4.18), the WHM 4.20 has 42 sets of lemma changes, 25 sets of changes from absolute to construct, 40 sets of changes from construct to absolute, 95 sets of other parsing changes (including changes to the part of speech), 6 changes involving an implicit definite article, 9 textual changes with an associated change in bracket notes, 33 other changes to bracket notes, and 30 other textual changes. We added a new part of speech, “demonstrative,” which is a special case of the adjective part of speech.
Changes to the text are to make the WHM and the WLC conform to the text of the Hebrew Bible found in the Leningrad Codex.
Corrections to parsings and lemmas are usually done in consultation with HALOT (Koelher, Baumgartner, and Stamm, third edition), though we sometimes disagree with HALOT, and occasionally HALOT is unclear or even (rarely!) inconsistent.
The WLC version 4.18 can be viewed in Unicode at http://www.tanach.us, which will soon be updated to version 4.20.