[css-grid-1][editorial] Actually dfn 'explicit grid tracks'.

Author: tabatkins

css-grid-1/Overview.bs

@@ -1394,7 +1394,8 @@ Defining the Grid</h2>
 The Explicit Grid</h3>
 
 	The three properties 'grid-template-rows', 'grid-template-columns', and 'grid-template-areas'
-	together define the <dfn export local-lt="explicit">explicit grid</dfn> of a <a>grid container</a>.
+	together define the <dfn export local-lt="explicit">explicit grid</dfn> of a <a>grid container</a>
+	by specifying its <dfn lt="explicit grid track | explicit grid row | explicit grid column">explicit grid tracks</dfn>.
 	The final grid may end up larger due to <a>grid items</a> placed outside the <a>explicit grid</a>;
 	in this case implicit tracks will be created,
 	these implicit tracks will be sized by the 'grid-auto-rows' and 'grid-auto-columns' properties.
@@ -5038,13 +5039,13 @@ Clarifications</h4>
 	<ul>
 		<li id="change-2017-implicitly-sized-explicit-tracks">
 			Clarified that 'grid-auto-rows' and 'grid-auto-columns' apply to
-			[=explicit tracks=] created by 'grid-template-areas'
+			[=explicit grid tracks=] created by 'grid-template-areas'
 			that are not assigned a size by 'grid-template-rows' or 'grid-template-columns'.
 			(<a href="https://github.com/w3c/csswg-drafts/issues/4914">Issue 4914</a>)
 			<blockquote>
 				<p>&hellip; These lines together with the <a>explicit grid</a> form the [=implicit grid=].
 				The 'grid-auto-rows' and 'grid-auto-columns' properties size these [=implicit grid tracks=]<ins>,
-				as well as any [=explicit tracks=] created by 'grid-template-areas'
+				as well as any [=explicit grid tracks=] created by 'grid-template-areas'
 				but not explicitly sized by 'grid-template-rows' or 'grid-template-columns'</ins></p>
 			</blockquote>
 			<blockquote>