In broad terms, you cannot make little bits of your service accessible and call the whole service accessible. We know this for a fact now because of last week’s ruling by the Supremes. Via Rail contended that, since some of its lines were accessible and a few other provisions were made, such an arrangement should be good enough. No, it isn’t (emphasis added):
The fact that there are accessible trains travelling along only some routes does not justify inaccessible trains on others. It is the global network of rail services that should be accessible. The ad hoc provision of services does not satisfy Parliament’s continuing goal of ensuring accessible rail services. To permit Via to point to its existing cars, which were to be phased out, and special service‑based accommodations as a defence would be to overlook the fact that while human rights law includes an acknowledgment that not every barrier can be eliminated, it also includes a duty to prevent new ones, or at least not knowingly to perpetuate old ones where preventable.
By extension, that means you can’t caption “everything” on your public broadcaster but not caption your specialty channels, your commercials, or your subtitled shows, or not audio-describe all or nearly all your programming, or produce inaccessible Web sites, or run video online without accessibility features. Sorry: It is the global network that should be accessible.