How Do You Catch a Foreign Patent Cited Twice in an IDS?

Because most offices number the filing, the publication and the grant separately. Some keep one number for the publication and the grant and change only the kind code. Others give the grant a new number, and those are where duplicates slip through.

When the number stays the same, a duplicate is easy to spot. When it changes, the two citations look unrelated unless you look them up.

Because KIPO numbers the filing, the unexamined publication and the granted patent separately. The formats are:

"10" marks a patent; utility models use "20". Search databases often drop the hyphens and add the country and kind code, so 10-NNNNNNN B1 may appear as KR10NNNNNNNB1.

Two features make Korean citations easy to get wrong:

• The application number and the A publication number share the same format. They are different serial numbers for different things. A number in the 10-YYYY-NNNNNNN format tells you nothing until you know which one it is, and one document's application number can match another document's publication number.
• There may be no A publication at all. If KIPO grants a patent before the application is laid open, the B1 is the only publication. An A-only lookup will miss it.

Yes. Since January 19, 2025, an IDS that pushes the cumulative count of applicant-provided items past 50, 100 or 200 owes a size fee under 37 CFR 1.17(v). The USPTO's quick reference guide answers the duplicate question directly:

• Each listing counts. The same item listed twice on one IDS, or once on each of two IDSs, counts twice.
• A corrected resubmission does not. If an item was not considered because it was non-compliant, listing it again in the same application is not counted a second time.
• Parent citations stay in the parent. Items cited in a parent application are not counted in a child unless you cite them again there.
• An RCE does not reset the count. The count runs from filing to issuance.
• The count is yours to keep. The guide says examiners are not expected to track it.

An A publication and a B1 registration of the same Korean application are two documents, so listing both is two items. Whether both belong on the IDS is a judgment for the practitioner. The point is to make that call on purpose, not to discover after filing that the same patent went in under two numbers.

1. Write every foreign number in one format. Country code, number, kind code: for Korea, KR, then the digits, then A or B1. A number with no kind code is not finished yet.
2. Look each one up. In the issuing office's database (KIPRIS for Korea) or Espacenet, find the application it belongs to and record three things: the application number, the publication number (if there is one) and the grant number (if granted). For Korea, those are the A and the B1.
3. Group by application number. The application number is the family key. Two citations under the same application are the same patent, even if every digit you were sent differs.
4. Compare against what is already of record. Check each group against the references in the US file wrapper: your earlier IDSs and the references the examiner cited. If the patent is already there under any of its numbers, decide whether listing it again serves a purpose. References the examiner cited do not count toward the size fee, but once you list one on your own IDS, that listing counts.
5. Update the running count. Add this IDS to the cumulative total and check it against 50, 100 and 200 before you file.

Three citations arrive for the same US application. Digits are masked; the formats match current Korean numbers.

All three are the same Korean patent. The A publication is already of record. The B1 is a new document from the same application, so citing it is a decision, not an automatic add. The email's number is an application number, which identifies a filing rather than a published document, so it would need to be resolved to the A or B1 before it could be cited at all. Without the lookup, the same patent could go into this file three times, once under a number that cannot be cited.

ClaimxArk builds the IDS from the email the references arrived in, and runs the Korean lookup described above as part of the draft:

• Korean numbers are resolved to their application number through KIPRIS, then compared with the references in your earlier IDSs. Matches are flagged with the IDS they were filed in.
• Examiner-cited lists are shown for you to check.
• The cumulative count is shown against the 50, 100 and 200 thresholds before you file.
• Every entry is shown next to its source page, so you can check each one against the original.

The practitioner still decides what to cite and signs the IDS.

See the two-minute demo. Or start free at claimxark.ai.