Form elements in accessibility strings

Hi all,

While going through the latest accessibility strings in Firefox
devtools (devtools/client/accessibility.ftl resource), many strings
take the following form:

"<code>fieldset</code> elements must be labeled."

But then I find a:

"Form elements must be labeled."

Is "Form" here referring to the `form` element, or rather to the
collection of form elements like e.g. `form`, `input`, `label`, etc.?

If it's the former, then a `<code>form</code>` would be preferable I
guess. Otherwise an explanatory comment wouldn't hurt.

Can someone please clarify this? Thanks in advance!

Julen.