Manual:$wgWikiDiff2MovedParagraphDetectionCutoff

Details
Wikidiff2 supports detection of changes in moved paragraphs. Supported values:
 * $$0$$: detection of moved paragraphs is disabled
 * $$int > 0$$: maximum number of paragraphs to compare

Note: Number of paragraph comparisons is in O($$n^2$$). This setting is only effective if the wikidiff2 PHP / HHVM module is used as diffengine. See.