This is a semi-standard Unicode "abuse": stacking many combining characters on one base character which causes some rendering engines in some contexts to display characters where the diacritics extend far beyond the usual line box, often overlapping adjacent lines.
See example here:
https://test2.wikipedia.org/w/index.php?title=Test_page_ugg&action=history
Enwiki VPT discussion: https://en.wikipedia.org/w/index.php?title=Wikipedia:Village_pump_(technical)&oldid=828758923#Strange_page_markings
Example: