[css-align] Shouldn't 'left'/'right' keywords definitions be simplified?

[SelenIT]

Currently, the CSS Box Alignment spec has the following note about left and right alignment values:

If the property’s axis is not parallel with either left↔right axis, this value behaves as start.

But given that these values are restricted to justify-* properties, isn't the property's axis parallel with the line left↔right axis in all cases except the flex-direction: column case in Flexbox layout? And if the writing-mode is vertical/sideways, than the main axis of the column-oriented flex container would be parallel with the physical left↔right axis. Also, the only justify-* property that is not ignored in Flexbox layout is justify-content.

So, if I haven't miss anything, the only situation where the the axis of the property that accepts the left and right values is not parallel with with either left↔right axis is the justify-content property in Flexbox layout where flex-direction: column; writing-mode: horizontal-* are in effect. If it is true, wouldn't the spec become more readable if we state this only exception explicitly? E.g.,

For the justify-content property of a flex container with horizontal writing mode and flex-direction: column, this value behaves as start.

[tabatkins]

I'm generally loathe to make these sort of higher-specificity edits; while we don't expect to define anything else that makes justify/align depend on something other than writing-mode (and consider our decision to do so in Flexbox to be a mistake), if for some reason we ever do, it's better for this text to correctly handle it.

As well, even if I did specialize it to Flexbox, I'd still want to include a note explaining why this exception exists, which would just restate the more generic rule that we just removed.

We do sometimes add notes explaining that the generic rule is actually equivalent to a more specific rule like you suggest, tho.

[fantasai]

Flag as needs edits to add a note. Agree 100% with @tabatkins logic.