Originally Posted by Jellby
As long as you use the text of the play (i.e., not whatever notes or introduction it may have), and you do substantial modifications to the formatting (and "nicely formatted epub" qualifies as that), I'd say you can ignore any copyright or license statement in the file. That is, assuming the text is really the public-domain play we believe it is.
But I am not a lawyer.
I believe Shakespeare can be a bit different than usual because there are a number of different versions of each Shakespeare play (Quaros, Folios etc). When someone edits the versions together (choosing which scenes to include and which versions of the stage directions to use) that version
of the play is copyrighted to that company e.g. The Oxfordian Shakespeare
I've decided to go with the World Library, Inc versions, anyway. And I've actually found quite a few OCR errors