According to us, three 
signs in bars 17-18 and 21, written by Chopin during a proofreading of FE, are long accents and they refer to b
1 notes of appoggiatura nature in the L.H. This kind of motifs are often to be found in Chopin's works, e.g., in the Nocturne in G minor, Op. 37, No. 1, bars 1-2 and analog., the Polonaise in E major, Op. 22, bars 111-112 and analog. In the editions the signs are longer and aligned rather under the R.H. The fact that the engraver of FE not always correctly recreated Chopin's entries is proved by distorted accents in the Etude in A minor, No. 2, bars 8 and 12. In the main text we also suggest to add the mark in bar 22.
In A the b1 notes in bars 17-18 and 21-22 were written instead of the original a1 notes.
Compare the passage in the sources»
category imprint: Graphic ambiguousness; Differences between sources; Editorial revisions; Corrections & alterations; Source & stylistic information
issues: Long accents, Corrections in A, Accompaniment changes, Authentic corrections of FE
notation: Articulation, Accents, Hairpins