"An answer is not immediately apparent,"

You have to work for it.

The first link I provided explained how it works and how it is assessed, and that each type of penalty and/or tax has its own expiration date. That's why you see (in your attachment) March and June, and June is on three issues. Then, it also explains what and how you might see delays, suspension, or extensions. If you can't figure out why something is listed, then along with the table of codes, you might be able to discern how and why,  such as in your attachment, you see that line with 0 value. Just as with any transcript, you look at each line to determine its impact to the overall process. You have three different things that show June dates right now, but that doesn't mean they will transpire together through the processes.

"Assessments with their own CSED include but are not limited to:

• Original tax assessments from voluntarily filed returns;
• Tax assessments arising from amended return filings;
• Substitute for Return (SFR) tax assessments filed by the IRS when an individual fails to file a return;
• Audit assessments; and
• Certain penalty assessments."

..."However, overlapping situations run simultaneously; the time for multiple events is not added more than once where one event may overlap another."

And you show an Offer In Compromise: "If you submit an Offer in Compromise (OIC), the running of the collection period is suspended from the date the offer is pending to the date the offer is accepted, returned, withdrawn, or rejected. If your Offer is rejected, the collection period is suspended for an additional 30 days and, if you file an appeal of the rejection, the collection period is suspended while the appeal is pending.

Tax Topic No. 204 can help you better understand the details of OIC agreements."

I assume you are working on something with notifications and some actions were taken at some time against some tax year filing.