[css-position-3] Import definition of ‘static-position containing block’ from CSS2.

Author: fantasai

css-position-3/Overview.bs

@@ -105,9 +105,6 @@ spec:css2; type:dfn; text:stacking context
 urlPrefix: https://www.w3.org/TR/CSS2/visuren.html; spec: CSS2;
 	url: #normal-flow; text: normal flow; type: dfn;
 	url: #x1; text: viewport; type: dfn;
-urlPrefix: https://www.w3.org/TR/CSS2/visudet.html; spec: CSS2;
-	url: #static-position; text: static position; type: dfn;
-	url: #static-position; text: static-position containing block; type: dfn;
 </pre>
 
 <pre class=link-defaults>
@@ -798,11 +795,11 @@ Absolute (and Fixed) Positioning</h3>
 
 
 <h4 id="staticpos-rect">
-Resolving Automatic Insets: the “Static Position Rectangle”</h4>
+Resolving Automatic Insets: the “Static-Position Rectangle”</h4>
 
 	When both [=inset properties=] in a given axis are ''left/auto'',
-	they are resolved into a <dfn>static position</dfn>
-	by aligning the box into its <dfn>static-position rectangle</dfn>,
+	they are resolved into a <dfn export>static position</dfn>
+	by aligning the box into its <dfn export>static-position rectangle</dfn>,
 	an [=alignment container=] derived
 	from the [=formatting context=] the box would have participated in
 	if it were ''position: static''
@@ -818,11 +815,10 @@ Resolving Automatic Insets: the “Static Position Rectangle”</h4>
 			are defined in [[CSS2]] Chapter 10.
 			The [=static-position rectangle=] is a zero-thickness rectangle spanning between
 			the inline-axis sides of the box’s [=static-position containing block=]
-			(see <a href="https://www.w3.org/TR/CSS2/visudet.html#abs-non-replaced-width">CSS2&sect;10.3.7</a>);
 			and positioned at its [=block-start=] [=static position=]
 			(see <a href="https://www.w3.org/TR/CSS2/visudet.html#abs-non-replaced-height">CSS2&sect;10.6.4</a>).
 
-			Note: In block layout the static-position rectangle corresponds to the position of the “hypothetical box”
+			Note: In block layout the [=static-position rectangle=] corresponds to the position of the “hypothetical box”
 			described in <a href="https://www.w3.org/TR/CSS2/visudet.html#abs-non-replaced-width">CSS2.1&sect;10.3.7</a>.
 			Since it has no alignment properties,
 			CSS2.1 always uses a <a>block-start</a> <a>inline-start</a> alignment
@@ -856,11 +852,14 @@ Resolving Automatic Insets: the “Static Position Rectangle”</h4>
 	</dl>
 
 	Finding the [=static position=] and the [=static position rectangle=]
-	assumes that both 'float' and 'clear' have their initial values,
-	and can require assuming a different hypothetical value
+	assumes that both 'float' and 'clear' (as well as 'position')
+	have their [=initial values=],
+	and can consequently require assuming a different hypothetical value
 	for 'display' as well.
+	(The [=containing block=] the element would have had under these conditions
+	is the <dfn export>static-position containing block</dfn>.)
 	To the extent the [=box alignment properties=] have an effect,
-	they use the [=static position containing block=]
+	they use the [=static-position containing block=]
 	as the effective [=containing block=],
 	including using its [=writing mode=] for resolving alignment axes and directions.
 	Additionally, the [=containing block=] of [=fixed positioned=] elements