plural noun: errata
an error in printing or writing.
  • a list of corrected errors appended to a book or published in a subsequent issue of a journal.

Page 5. There are no steps missing, it is just mis-numbered. I'm surprised you noticed. Good job.
Page 8. Cornerstones are optional if the side borders are long enough.

Triangle Frenzy Whirlwind
Updated directions. Step 14 DO NOT sew halves together yet.
Step 17 After sewing on setting triangles. Trim to straighten edges. Now sew the two halves together.