Mark the experimental property as deprecated

[ddbeck]

Summary

Consumers of BCD probably shouldn't use the experimental field.

Test results and supporting details

In the October 21, 2025 BCD meeting, I suggested this as a possibility. I'm finally getting around to it!

Related issues

n/a

[github-actions]

Tip: Review these changes grouped by change (recommended for most PRs), or grouped by feature (for large PRs).

[caugner]

Suggested change

	**Warning**: The `experimental` property is deprecated. Prefer using more well-defined stability calculations, such as Baseline, instead.
	> [!WARNING]
	> The `experimental` property is **deprecated**.
	> Prefer using better defined stability calculations, such as Baseline, instead.

[ddbeck]

Unfortunately, this won't work. GitHub's (non-standard, unspecified 🙄) admonitions don't work in a list. They only render if the > is at column 1.

[foolip]

I'm excited for this!

[caugner]

Consumers of BCD probably shouldn't use the experimental field.

BCD tables on MDN show an icon for experimental features. We could instead show a Baseline icon, but we would probably have to compute it directly from each BCD feature, without taking into consideration web-features.

I would propose to add this computed Baseline status per BCD feature into the published BCD data, and to do this at the same time of deprecating experimental.

[caugner]

We should wait with the deprecation until we provide a per-feature replacement of the experimental status, see my previous comment.

[ddbeck]

I don't think we should wait. This advice would be to new consumers of BCD: they should not use experimental for any purpose. But existing consumers of BCD may (at least until there's a plan to remove experimental).