An errata sheet is a common method of post-production editing in which the errors left in the produced copy are outlined on a sheet of paper bound into the book. This is a common method by which large works are "edited"; i.e. if the volume would cost too much and/or be too cumbersome to correct internally, this is an acceptable method by which one might edit the work.
It should be noted that errata sheets should only outline minor errors within a work (e.g. misspellings, improper punctuation and the like). If a major error in the construction of a sentence occurs, or if the construction is such that the sentence is ambiguous or confusing, this must be corrected within the work.