How do I make sense of the "同古同" that often appears in Pleco's《现代汉语规范词典》？

[hummus_082]

There's a character, namely "孛", and it has two pronunciations. One of those pronunciations is "bo2". If you were to look up this character/pronunciation combination in the《现代汉语规范词典》on Pleco (it seems to me that the version of this dictionary that is used is the third version), you would get the following entry: " 同古同“勃” ". The phrase "同古同" doesn't make much sense to me, and I've been suspecting today that perhaps this is an error on Pleco's part. It seems like the initial "同" in front is not supposed to be there. For the record, if you look up the same character on the built-in《现代汉语规范词典》dictionary on macOS (I believe the second edition is used), you would get " 古同“勃” ". What's going on here? How do I make sense of this?

 

[mikelove]

Probably a glitch in the data, yes - we use 3/e, and I believe Apple also licensed theirs through a second publisher while we licensed it directly from FLTRP, so lots of reasons the data might differ.