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


b. 3-4

composition: Op. 50 No. 3, Mazurka in C♯ minor

c2 repeated in AI & AF (→FEEE)

c2 tied in GE

..

The version with tied c2, coming probably from [AG] (→GE), is undoubtedly later, hence we give it directly in the main text. Admittedly, Chopinesque proofreading of FE took place even later, yet the fact that a tie was not added here does not allow us to draw conclusions that Chopin returned to the original concept, since the difference could have been of less importance to the composer, hence he could have forgotten it while proofreading FE.
There is a similar situation in b. 7-8 and 95-96.

category imprint: Differences between sources; Corrections & alterations

b. 3

composition: Op. 50 No. 3, Mazurka in C♯ minor

..

In the main text we add a cautionary  before b1.

category imprint: Editorial revisions

b. 3-4

composition: WN 37, Lento con gran espressione

..

In A1 the last three chords of the introduction are written with the use of one-part notation.

category imprint: Differences between sources; Corrections & alterations

b. 3-4

composition: WN 37, Lento con gran espressione

c1 repeated in A1

c1 tied in CJ, CK (→CB) & EL

..

The missing tie of c1 is probably Chopin's oversight in A1, hence we consider it acceptable to add it in the text of A1.

category imprint: Differences between sources

issues: Errors of A

b. 3-19

composition: Op. 28 No. 2, Prelude in A minor

One-voice notation in A (→FCGE, →FEEE)

Two-voice notation in CGS

..

Just like in b. 1-3, later in the Prelude, CGS consistently stuck to a different division into parts, indicating the R.H. to perform the topmost notes on the bottom stave. The only exception are b. 6-7, in which the smaller span of figuration makes it possible to be performed entirely by the L.H. 

category imprint: Differences between sources