1.1.1 Divergent language of the image short alternative text

[LaurenceZaysser]

1.1.1 Non-text-content

In academic work, you may find images containing text in another language than the publication's one.
In this case, the short alternative text must also be written in this other language (i.e. not translated, in order to provide an equivalent service to visually impaired readers). So that assistive technologies may render it in the proper language, it is necessary to specify the language of the image in this case. It can be with an alt attribute on the img element (or its block parent). As it is a global attribute, people often forget about it and do not know it can apply to every HTML element, including non-textual elements.

Could you add a new FAILURE to cover this usecase? It could be entitled like this.
FXXX: Failure of Success Criterion 1.1.1 due to missing lang attribute when the language of an image short alternative text differs from the text around the image.

[patrickhlauke]

if the failure is "the alt is correctly in the different language, but the change of language has not been indicated", then that's not a failure of 1.1.1 but of 3.1.2 Language of Parts.

it would be a 1.1.1 failure if the alt was translated but the image had text content in the other language, as then the alt isn't equivalent

(and the usual reminder that techniques aren't exhaustive, and there can be many more ways to pass or fail a particular SC even if a positive technique or failure technique hasn't been written to cover that particular scenario)

[LaurenceZaysser]

You are right. There are two types of failures indeed, connected to either 1.1.1 or 3.1.2.

The definition of 3.1.2 Language of Parts could explicitly mention that "parts" can be either textual and/or non-textual elements.
And its sufficient technique H58 could be completed to explain that the lang et srclang attributes on non-textual elements (img, audio, video/track) are dedicated to assistive technologies that restitue alternative texts (alt on img, src on track).