John 20:30
Jesus performed many other signs in the presence of His disciples, which are not written in this book.
What it says
Jesus did many other signs before his disciples, but John does not write them all in this book here either.
What it is doing
The book is selective rather than exhaustive, choosing signs for a stated purpose in writing.
In context
30Jesus performed many other signs in the presence of His disciples, which are not written in this book. 31But these are written so that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in His name.