In How can I repair a split in a board?, the accepted response suggests a "dutchman patch," but I'm getting mixed messages from various sources. Some show a dutchman as being the removal of damaged material and insertion of a patch of the same size. Others seem to specifically be a bowtie/butterfly shape reinforcing a crack in wood.
For instance, both of these images are being referred to as dutchman patches:
So which is it? Is there a difference between a dutchman patch and a butterfly patch? Is this just a case of the same phrase meaning two different things?
Is a dutchman a general term and the buttefly specifically that shape of dutchman?