How should patent examiners treat reference characters in claims?

Patent examiners should treat reference characters in claims as helpful cross-references that do not affect the claim’s scope. According to MPEP 2173.05(s), “Generally, the presence or absence of such reference characters does not affect the scope of a claim.“

Examiners should:

• Consider the claim language independently of the reference characters.
• Use the reference characters to understand the relationship between claim elements and the description/drawings.
• Not interpret the reference characters as limiting the claim scope unless explicitly stated in the claim.
• Refer to MPEP § 608.01(m) for additional guidance on treating reference characters in claims.

Examiners should focus on the actual claim language and use the reference characters as aids for interpretation rather than as claim limitations.

To learn more:

• patent examination
• reference characters
• claim interpretation
• MPEP 2173.05(s)