According to the spec at https://wicg.github.io/aom/spec/aria-reflection.html#AriaAttributes attributes for element references are named without any suffix, e.g. ariaDescribedBy.

However that doesn't match the implementation in Chromium that includes a Elements suffix, e.g. ariaDescribedByElements.

In the ARIA Reflection Explainer, the version with the suffix is used: https://wicg.github.io/aom/aria-reflection-explainer.html#reflecting-element-references

ARIA spec though suggests the name shouldn't have a suffix in a non-normative section: https://w3c.github.io/aria/#idl_attr_disambiguation (filled an issue on ARIA spec too w3c/aria#1724)