Examples:

https://en.wikipedia.org/w/index.php?title=Saharan_silver_ant&diff=next&oldid=667642138 (<ref name="Gullen"> becomes <ref name=":0">)

https://en.wikipedia.org/w/index.php?diff=699740332&oldid=699740164 (<ref name="Gullen"> becomes <ref>; <ref name="Greenland"> becomes <ref name=":0">)

If a ref name already exists, then please don't change it when changing the contents of the ref tag.