Depending upon the context, the term prophecy can refer to all of the Bible, not just a particular portion or book (such as Revelation).

2 Peter 1:19-21 We have also a more sure word of prophecy; whereunto ye do well that ye take heed, as unto a light that shineth in a dark place, until the day dawn, and the day star arise in your hearts: Knowing this first, that no prophecy of the scripture is of any private interpretation. For the prophecy came not in old time by the will of man: but holy men of God spake as they were moved by the Holy Ghost.

God doesn't want man to add to, take away from, change, twist or wrest any part of Scripture.