+* (T174032) action=compare now supports multi-content revisions.
+ * It has a 'slots' parameter to select diffing of individual slots. The
+ default behavior is to return one combined diff.
+ * The 'fromtext', 'fromsection', 'fromcontentmodel', 'fromcontentformat',
+ 'totext', 'tosection', 'tocontentmodel', and 'tocontentformat' parameters
+ are deprecated. Specify the new 'fromslots' and 'toslots' to identify which
+ slots have text supplied and the corresponding templated parameters for
+ each slot.
+ * The behavior of 'fromsection' and 'tosection' of extracting one section's
+ content is not being preserved. 'fromsection-{slot}' and 'tosection-{slot}'
+ instead expand the given text as if for a section edit. This effectively
+ declines T183823 in favor of T185723.