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b. 276-277

composition: Op. 35, Sonata in B♭ minor, Mvt II

Slur up to beginning of bar 277 in GC & FE (contextual interpretation)

Slur up to beginning of bar 276 in GE

Slur up to end of bar 276 in FE (literal reading→EE)

..

Leading the slur in GC until bar 277 is obvious, in spite of the lack of the slur's ending in a new line – in bar 276 (at the end of the line) both the slur and the tie of bgo far beyond the bar line and none of them is finished afterwards, which points to an oversight of the person who was writing. The fact of shortening the slur in GE must be then considered a missed revision. In FE the situation is analogous to GC – both curved lines, reaching the end of the line in bar 266, suggest continuation, which, however, does not follow (FE4 finished the tie). In spite of this, the engraver of EE interpreted each of these curved lines differently – the tie is led to bin bar 277 but the phrase mark only to bar 266.
From the practical point of view, all three notations mean the same thing.

category imprint: Graphic ambiguousness; Differences between sources

issues: Inaccuracies in FE , GE revisions , Inaccuracies in GC

b. 276

composition: Op. 21, Concerto in F minor, Mvt I

..

Same as in analogous bar 128, in A there is no accidental before the crotchet in the middle voice. It must be an oversight, corrected already in GE1 (→FEEE, →GE2).

category imprint: Interpretations within context; Differences between sources

issues: Omission of current key accidentals , Authentic corrections of GE , Last key signature sign , Inaccuracies in A

b. 276-278

composition: Op. 21, Concerto in F minor, Mvt I

Slur in bar 278 in A (literal reading)

2 slurs in GE (→FE)

2 slurs in EE

Slur in bars 276-278 suggested by the editors

..

In A bar 277 is the last one on the page and it does not contain phrase marks. In turn, in bar 278 there is a slur suggesting a continuation from the previous bar. Therefore, it seems that Chopin forgot to write the initial part of the slur, most probably of the one with which he embraced that phrase in bars 128-130. This is the slur we suggest in the main text. In GE, next to the slur in bar 278, roughly reproduced, a slur of a similar range was added also in bar 277. If the implemented proofreading had been inspired by Chopin, which cannot be excluded, it would be a correction of an ad hoc nature rather than an intended variation of phrasing.

category imprint: Graphic ambiguousness; Interpretations within context; Differences between sources

issues: Inaccurate slurs in A , EE inaccuracies , Authentic corrections of GE

b. 276

composition: Op. 21, Concerto in F minor, Mvt I

Quaver c1 in A & FE (→EE)

Crotchet c1 in GE

..

A line pointing down next to ledger lines (most of the time the first bottom one, i.e. c1 or E – see e.g. the last E in bar 280), sometimes appearing in Chopin's autographs, misled here the engraver of GE. The additional stem is already absent in FE (→EE), which could have been, but did not have to, a result of Chopin's proofreading. However, one has to admit that in this case the extension of cis quite reasonable, as far as the harmony is concerned. 

category imprint: Graphic ambiguousness; Differences between sources

issues: Authentic corrections of FE , Uncertain notes on ledger lines

b. 276

composition: Op. 11, Concerto in E minor, Mvt I

No fingering in FE (→GE)

Fontana's fingering in EE

Fingering written into FEH

..

The authenticity of the discrepant indications of EE and FEH is not confirmed.

category imprint: Differences between sources

issues: Annotations in teaching copies , EE revisions , Annotations in FEH