Select: 
Category
All
Graphic ambiguousness
Interpretations within context
Differences between sources
Editorial revisions
Corrections & alterations
Source & stylistic information
Pitch
All
Pitch
Rhythm
Slurs
Articulation, Accents, Hairpins
Verbal indications
Pedalling
Fingering
Ornaments
Shorthand & other
Importance
All
Important
Main


Pitch

b. 83

composition: Op. 25 No 12, Etude in C minor

C1-C in FC (→GE), FE & EE2 (→EE3)

C in EE1

..

The missing bottom C1 in EE1 is most probably a mistake, corrected in EE2 (→EE3), perhaps on the basis of FE.

category imprint: Differences between sources

issues: EE revisions , Errors in EE , Abbreviated octaves' notation