The signs, introduced most probably with Chopin's hand to FED in bars 151, 153 and 155, are problematic to interpret. The sign in bar 153 is certainly 
, yet both signs in bars 151 and 155 look like narrow, diagonal crosses that can be interpreted as 
only in comparison with the mentioned . Such defined echo effect brings new interpretation possibilities of this fragment; authentic, although not resulting from the basic notation. According to us, the teaching comments, however, may not be regarded as generally valid, hence in the main text we suggest them in brackets, leaving their inclusion to the discretion of the performer.
Compare the passage in the sources »
category imprint: Differences between sources
issues: Annotations in teaching copies, Annotations in FED
notation: Verbal indications