[css-contain] Terminology question

[frivoal]

Taken from a comment of @MatsPalmgren in #4931 (comment)

BTW, is "containing box" really a good term to use? Isn't "container's box" clearer? Or perhaps "principal box" would be better since it's an already established term.

I feel that @MatsPalmgren has a point. Between "containing block" and "block container box", we have enough similar/confusing terminology already, and adding containing box to that isn't great, and we probably should have picked something better. Since this is just terminology, with no impact on any implementation, we can still change if we find something better.

That said, I don't think "container's box" helps with the terminology overload.

"principal box" isn't wrong, but it's not specific enough either, because we're trying to talk about a particular one. The definition for which we'd like a name is:

The principal box of the element to which containment is applied

Maybe "containment box", possibly qualified to "size containment box", "layout containment box", or "paint containment box" as appropriate? This is still a bit too close for comfort to "containing block" and "block container box", but at least the word "containment", even if similar, is never used in any other context.

cc @tabatkins

[rachelandrew]

Agreed, I think containment box would definitely be better than anything that might tangle the definition in people's minds with containing block.

[css-meeting-bot]

The CSS Working Group just discussed Terminology Question for css-contain, and agreed to the following:

• RESOLVED: Change term "containing box" to "containment box"

The full IRC log of that discussion

<fantasai> Topic: Terminology Question for css-contain
<fantasai> github: https://github.com//issues/5590
<fantasai> florian: Spun out from bigger discussion, and mats_ pointed out we used the term 'containing box' to talk about the principal box of element to which containment is being applied
<fantasai> florian: 'containign box' sounds a lot like 'containing block'
<fantasai> florian: he proposes 'containers box', I don't love that either
<fantasai> florian: but 'contaiment box' maybe helps?
<fantasai> florian: help avoid confusion with 'containing block'
<fantasai> florian: purely editorial
<fantasai> +1 to changing
<TabAtkins> q+
<fantasai> florian: Used half a dozen times in this spec, not really in other specs (yet)
<heycam> +1 to "containment box"
<fantasai> TabAtkins: +1 to changing
<astearns> ack TabAtkins
<fantasai> TabAtkins: "containing" is used too much across CSS
<fantasai> TabAtkins: "containment box" sounds great, directly ties into concept, and slightly more distinct
<fantasai> RESOLVED: Change term "containing box" to "containment box"