Issues : Errors in FE

b. 19

composition: Op. 28 No. 15, Prelude in D♭ major

Crotchet g in A (→FC)

No crotchets in FE (→EE1) & GE

Crotchets g & a in FED, FES & EE2

..

The stem prolonging the g quaver was overlooked both in FE (→EE1) and GE). Chopin added it in FED and FES; moreover, in both copies he also prolonged the last a quaver. We consider that addition, most probably introduced independently in each of the copies, a development of the original idea and adopt it to the main text.
It remains a mystery how the reviser of EE2 found out about those prolonged notes. 

category imprint: Differences between sources

issues: Annotations in teaching copies , EE revisions , Errors in FE , Annotations in FED , Errors in GE , Annotations in FES

b. 43

composition: Op. 28 No. 15, Prelude in D♭ major

 under 3rd quaver  in A (→FCGE)

No marking in FE (→EE1)

on 2nd quaver in EE2

..

The missing  indication in FE (→EE1) must be the engraver's oversight. Dynamic gradation is undoubtedly an integral part of the 16-bar section that ends here; as a result, the dynamics of the beginning of its repetition should be tantamount to sotto voce in b. 28. It is also confirmed by  present in the next bar in FED.

In EE2 the indication was probably repeated after GE. Moving it a quaver earlier was an arbitrary decision; however, it may comply with Chopin's intention, since he would sometimes place markings within the range of their scope, and not at the beginning.  

category imprint: Differences between sources

issues: EE revisions , Errors in FE

b. 87

composition: Op. 28 No. 15, Prelude in D♭ major

Accent in A, interpretation

No mark in FC (→GE) & FE (→EE)

..

The Chopinesque manner of writing semibreves in the middle of the bar, now almost completely abandoned (cf. General Editorial Principlesp. 24), was used in this bar to indicate that the accent refers to e1, which, therefore, belongs to the bottom, melodic voice of the R.H. Semibreves are written down in this way in A (→FC,FE) in the entire ending (b. 84-89), which, in this case, we reproduce in the graphical transcription as an exception (the version "transcription"). However, the accent was not reproduced in any other source – Fontana overlooked all dynamic indications in b. 83-87, while in FE all 3 notes of the chord in the discussed bar were written in the middle of the bar, which impeded the accent to be placed in accordance with Chopin's intention. 

category imprint: Differences between sources; Source & stylistic information

issues: Long accents , Errors in FE , Errors of FC