Instead of 
present in the final version in b. 28, FCI features a 
mark already in b. 27, which is then repeated in b. 30. As in many other places, Chopin reduced the number of dynamic indications while preparing the Prelude for print; in this case, however, he added leggiero to specify the mark. In EE1 leggiero was most probably overlooked by the engraver, which was corrected in EE2, probably after having compared it with GE1.
Compare the passage in the sources »
category imprint: Differences between sources; Corrections & alterations
issues: EE revisions, Errors in EE
notation: Verbal indications