[css-grid-2] Clarify placement of items placed outside the subgrid’s explicit grid. #2564

Author: fantasai

css-grid-2/Overview.bs

@@ -176,6 +176,22 @@ Characteristics of a Subgrid Item</h3>
 			These names are in <em>addition</em> to
 			any line names specified locally on the subgrid.
 
+
+		<li id="subgrid-implicit">
+			The <a>subgrid</a> does not have any <a>implicit grid tracks</a>
+			in the subgridded dimension(s).
+			Hypothetical <a>implicit grid lines</a> are used to resolve placement
+			as usual when the <a>explicit grid</a> does not have enough lines;
+			however
+			each <a>grid item</a>’s <a>grid area</a>
+			is <a>clamped</a> to the subgrid’s <a>explicit grid</a>
+			(using the same procedure as for clamping placement in an overly-large grid).
+
+			<div class="example">
+				For example, if a ''span 1'' subgrid has a <a>grid item</a> with ''grid-column: 2 / span 3;'',
+				then that item is instead forced into (and limited to) the first (only) track in the subgrid.
+			</div>
+
 		<li id="subgrid-size-contribution">
 			The <a>subgrid</a> itself lays out as an ordinary <a>grid item</a> in its parent grid,
 			but acts as if it was completely empty for sizing purposes
@@ -341,16 +357,6 @@ Characteristics of a Subgrid Item</h3>
 				</dl>
 			</div>
 
-		<li id="subgrid-implicit">
-			The <a>subgrid</a> does not have any <a>implicit grid tracks</a>
-			in the subgridded dimension(s);
-			every <a>grid area</a> within it is <a>clamped</a> to its <a>explicit grid</a>.
-
-			<div class="example">
-				For example, if a ''span 1'' subgrid has a <a>grid item</a> with ''grid-column: 2 / span 3;'',
-				then that item is instead forced into (and limited to) the first (only) track in the subgrid.
-			</div>
-
 		<li id="subgrid-box-alignment">
 			The <a>subgrid</a> is always stretched in its subgridded dimension(s:
 			the 'align-self'/'justify-self' properties on it are ignored,