Please be aware that we have had and may continue to have huge surges of suggested edits on the site.
An anonymous user apparently is using a script to replace special characters with differently encoded equivalent symbols or their html representation. These edits usually have meaningless description messages, and especially in the areas of preformatted text, the html representations are detrimental to the readability.
What to do:
If you see a suggested edit on one of your posts, please check whether it is an actual improvement. Please reject suggested edits that don't improve the post.