There are four places in A (here and in bars 11, 36 and 57), where bass notes are furnished with dots. Those dots seem to be staccato dots, yet strangely none of them appears in GE (→FE→EE). The dots in bars 11 and 36 are placed higher than foreseen by rules of musical notation (this specifically applies to the dot in bar 11), yet this can be explained by corrections (erasures) that Chopin made in those places.
We often come across staccato dots over bass notes in similar contexts in Chopin's works, also complete with slurs (the slurs in bar 1 of the Nocturne are surely given as a model to be followed and are binding throughout the entire piece). Cf. for example Etude in A flat op. 10 no.10, bars 1, 7 and 16, or Ballade in F op. 52, bars 2, 4 and 12.
On the other hand, in A similar dots can be found in places not connected with the notation of the Nocturne, e.g. in bars 11 and 57. Thus, the accidental nature of some or all of the dots cannot be ruled out and therefore we always give them in parentheses as optional.
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category imprint: Differences between sources
notation: Articulation, Accents, Hairpins