[Arcorann]

I disagree with your characterisation as "horseshit" -- although eleven of the characters were subsequently located in other texts, these texts are different from the sources that were supposedly cited when they were input into JIS C 6226 in 1978 [1]. Of the twelve characters cited as "ghost characters", nine of them had claimed sources, but on further investigation were not in the claimed sources or were data entry errors of similar characters in those sources, while three did not have any claimed sources, of which two were later found in other texts (and one of those is believed to be an error), and 彁 has never been located in any text predating its input into JIS C 6226.

[1] https://ja.wikipedia.org/wiki/%E5%B9%BD%E9%9C%8A%E6%96%87%E5...

[lifthrasiir]

The problem is that we don't, and probably never will, be able to know if it was actually used or not. Chinese characters are very flexible and the phonosemantic construction of 彁 is fully justified, we couldn't just attest it (before 1978). The term "ghost characters" is merely colloquial and doesn't correctly reflect the reality of standards.