1.4.10 clarification (again) on "without loss of information or functionality" in relation to landscape aspect ratios

[patrickhlauke]

This probably rehashes/covers some of the ground already discussed in #1188 #987 #366 but it would be good to finally get some form of consensus:

Assume the scenario where a site that nominally has "vertical scrolling content" has, when viewed at 320x256 CSS px viewport (which is the situation the understanding document purports to address, where a user on a medium-sized 1280x1024 display is zooming to 400%), content that is never visible/reachable because it is cut off or covered by sticky page elements. Not just "they only have a small sliver of space to see the content" (but still can, even though it's difficult), but when it goes to the extreme of "they've not added sufficient padding/spacing at all, meaning the content/controls are never in view).

Does this normatively pass because the content is "vertical scrolling content", so we only care about the 320 CSS px width and as long as nothing gets cut off horizontally and/or causes bidirectional scrollbars (with exceptions) is a pass? Or do we nonetheless - based on the intent of the SC - note that while in terms of the width everything is fine (nothing is cut off/causes bidirectional scrollbars), the reduced vertical viewport height is causing content to be cut off and therefore it's a " loss of information or functionality"?

There do seem to be different interpretations in use in the wild, which is causing confusion.

[patrickhlauke]

The main point for me is to understand if the "without loss of information or functionality" part is also supposed to be scoped to only look at whether the content is vertical scrolling or horizontal scrolling, of it that part applies to both dimensions (since that's the scenario of desktop user zooming to 400% that the understanding purports to address with the SC), and that it's only the bidirectional scrolling part that distinguished based on horizontal scrolling content/vertical scrolling content.