[whatwg] Why is the legend element not categorized as flow content?

[Tab Atkins Jr.]

On Mon, Mar 29, 2010 at 7:02 AM, divya manian <divya.manian at gmail.com> wrote:
> On Sun, Mar 28, 2010 at 8:40 PM, Ian Hickson <ian at hixie.ch> wrote:
>> In what sense is it listed under phrasing content?
>
> The content model for the legend is stated as phrasing content in the spec [1]

"Content model" describes what the element is allowed to *contain*.
"Categories" describe what the element *is*.  (And then "Context..."
describes where it can be used.)

So <legend> can contain any phrasing content, but it isn't phrasing
content itself.

>> It's just supposed to be a child of <fieldset>, so it doesn't have any
>> category at all.
>
> Thanks, the general rule [2] that is given in the spec seems to
> include almost every known HTML4 element as flow content, but then,
> legend somehow is not a flow content (even though it fulfills the
> General Rule). I am trying to figure out if there is an easy way to
> know which elements are flow or not other than referring to the spec
> for each element before using.

If an element has special rules about where it can be placed, it's
probably not flow content.  That captures the <legend> issue, at
least, since it can only occur as the first child of <fieldset>.

~TJ