I am redoing the code we use to parse ITEM sections for indexing. I was reviewing the exceptions today and I came across something fascinating (to an EDGAR geek at least).

The lease note in the 10-K for PPL Corp (Ticker PPL; CIK 922224) is present but not visible in their 10-K for the last two fiscal years. Here is a link to their latest 10-K (PPL 12/31/2025 10-K). If you do a search in the document there is an index to the notes to the financial statements on page 99. There is no lease related note in that schedule.

The lease note is visible in our platform version of the file we processed for PPL and each of the subsidiaries but it appears before the actual cover page for the 10-K. Below is a screenshot of the results of a search for 10-K filings – the filing in the document pane is PPL CORP’s 10-K. Although this is difficult to confirm from the screenshot, the document viewer is positioned at the very top of the filing. The lease disclosure appears in our processed version before the filing’s cover page.

This is not visible in the filing accessed through EDGAR – the content exists but is placed before the cover page content and it is tagged to be hidden. Here is a simplified sketch of the html structure that causes this content to be invisible:

<div style="display:none">
  <ix:header>
    <ix:hidden>
      <ix:nonnumeric
        name="us-gaap:LesseeOperatingLeasesTextBlock"
        id="f-3742"
        contextref="c-1"
        escape="true">
        ...
      </ix:nonnumeric>
    </ix:hidden>
  </ix:header>
</div>

Processing these filings is complicated. Because this content was contained within the Inline XBRL header, and our processing attempts to preserve header content, the lease note remained in our version of the filing.

The characterization of this content as a lease note is also supported by PPL’s 2023 Form 10-K. That filing included a visibly rendered “Note 10. Leases,” and the disclosure embedded—but not visibly rendered—in the subsequent filings is substantially similar to the visibly rendered Note 10 in the 2023 Form 10-K.

This surfaced because I kept seeing an exception while trying to improve our TOC engine and initially I thought I had a logic problem. I finally looked closer at our version of the filing and started off thinking that we must have done something wrong during parsing. It was only after screen printing the EDGAR version code while comparing it to our version and looking more closely at the tagging structure that I relaxed – we didn’t mess up!

This appears to be a filing-construction error rather than an absence of the disclosure. The lease note exists in the filed Inline XBRL document, but the document’s HTML structure prevents it from being displayed through EDGAR. It also illustrates why processing EDGAR filings involves more than simply extracting the text that appears on the screen: sometimes important content is present in the source even though a reader cannot see it.