• Go to https://beta.musicbrainz.org/place/create
• Type "x" into the Coordinates field and immediately backspace, before the server had time to respond to the parsing request.
• Result: The field is empty, but shortly after, it is marked red and the message "These coordinates could not be parsed" appears.

In a similar way, responses to parsing requests could arrive out of order, meaning that, e.g., the last character typed could be ignored.