Contacts with X-APPLE-OL-MAPPING-INFO:1

Of my 2000+ iCloud contacts 175 have

EITHER the text "X-APPLE-OL-MAPPING-INFO:1" appended to the phone number

OR a much longer text string eg. "X-APPLE-OL-NOTE;TYPE=text/rtf;X-COMPRESSION=X-OL;X-HASH=6f513f3c4928fb6d3437d78a8b8cfe73;X-HASHALGORITHM=X-zMD5;ENCODING=B:tgAAAMgAAABMWkZ1cUMLLwMACgByY3BnMTI1FjIA+Atgbg4QMDMzTwH3AqQD4wIAY2gKwHOgZXQwIFYEkGQAcNphAoB9CoAAACoJsAnwqQSQYXQFsVIN4GgJgAEB0CA1LjQwLjEwMS4yMg4gAoBcdkkIkHdrC4BkNAxgYw8AUAsDC7UH8E9CSU4AIEdSQUVNRSBARFVSU1RPFoAmACBMWU5EQS1KhEFOFvBXQVRTF2EXCqIKgBIBABlw" appended to a note for the contact.

Bizarre

Do I have to plod through all 175 contacts to manually correct this?

Will it happen again?