Check out his posting on "mold cavity half-leaf repair marks". We have all seen these on bottles, there was an article on these marks in the "Antique Bottle and Glass Collector". I have a Shriver's Oyster Ketchup with that exact mark, I just sold a Boley soda with similar mark.
Interesting stuff... hat tip to Red Mathews
here's the link:
Half leaf "repair mark"~~ not so much. Not a repair patch to the bottle. Not a repair to the mould.
As reported by Warren F., most likely a mark or anomaly created by the pinching and then re-centering of a bottle during the early stage of bottle formation.
Probably newer than the bottles we are talking about in this post.
That mould boy on the upper right looks like a bottle pincher to me.