A patent may be corrected or amended in four ways, namely:

1. (A) by reissue,
2. (B) by the issuance of a certificate of correction which becomes a part of the patent,
3. (C) by disclaimer, and
4. (D) by reexamination.

The first three ways are discussed in this chapter while the fourth way (reexamination) is discussed in MPEP Chapter 2200 for ex parte reexamination and MPEP Chapter 2600 for inter partes reexamination.