This page is an FAQ based on guidance from the Manual of Patent Examining Procedure. It is provided as guidance, with links to the ground truth sources. This is information only: it is not legal advice.
Cross-references in patent classification are additional classifications assigned to a patent beyond its original classification. They are determined as follows:
- All mandatory classifications not selected as the original classification become cross-references.
- Additional discretionary classifications may be added by the examiner.
- Cross-references must be indicated on the IFW issue classification form.
The MPEP states: Once the original classification is determined, all remaining mandatory classifications are designated as cross-references, as are any additional discretionary classifications that the examiner wishes to apply to the patent.
It’s important to note that Digests and cross-reference art collections should also be included in the issuing classification boxes on the IFW issue classification form, but the original classification must never be a digest or cross-reference art collection.