I was sure I'd already filed an issue for this, but maybe it was for the old MDN site...

Take a look at this table:
https://developer.mozilla.org/en-US/docs/Web/API/FetchEvent/replacesClientId#browser_compatibility

The data for Edge being rendered here is:

"edge": {
  "version_added": "18",
  "version_removed": "79"
},

This is rendered as "18 — 79" on a red background. I think the natural interpretation of this that the feature was in versions 18-79, but the correct interpretation is that it was in Edge 18 only.

I think the logic here should be:

• The displayed end range is the version before version_removed in BCD.
• If that is the same as the start range, show just a single number on red, "18" in this case.

cc @Elchi3 @ddbeck