[css-nav-1] Add the name to the argument

Add the name to the argument for clearer reference

Author: Jihye Hong

css-nav-1/Overview.bs

@@ -482,7 +482,7 @@ the User Agent must run the steps described below:
 ::
     1. Return the nearest ancestor of the element that is a <a>spatial navigation container</a>,
         or the <a>document</a> if the nearest <a>spatial navigation container</a> is the viewport.
-    
+
     Note: If the element is a <a>spatial navigation container</a>, {{getSpatialNavigationContainer()}} also returns
     the nearest <a>spatial navigation container</a>, not the element itself.
 
@@ -987,8 +987,8 @@ To run the <dfn>spatial navigation steps</dfn> in <var>direction</var>, do the f
     * Else, if <var>searchOrigin</var> is either a <a>scroll container</a> or the <a>document</a>
         1. Let <var>candidates</var> be the result of <a>finding focusable areas</a>
             within <var>searchOrigin</var>
-            with the argument set to <code>false</code> if computed value of the 'spatial-navigation-action' property on <var>searchOrigin</var> is ''spatial-navigation-action/focus''
-            or to <code>true</code> otherwise.
+            with the argument <var>visibleOnly</var> set to <code>false</code> if computed value of the 'spatial-navigation-action' property on <var>searchOrigin</var> 
+            is ''spatial-navigation-action/focus'' or to <code>true</code> otherwise.
         2.
             * If <var>candidates</var> contains at least 1 item:
                 1. Let <var>bestCandidate</var> be the result of <a>selecting the best candidate</a>
@@ -1009,7 +1009,7 @@ To run the <dfn>spatial navigation steps</dfn> in <var>direction</var>, do the f
 6. Let <var>container</var> be the nearest ancestor of <var>eventTarget</var> that is a <a>spatial navigation container</a>.
 7. <i>Loop</i>: Let <var>candidates</var> be the result of <a>finding focusable areas</a>
     within <var>container</var>
-    with the argument set to <code>false</code>
+    with the argument <var>visibleOnly</var> set to <code>false</code>
     if computed value of the 'spatial-navigation-action' property on <var>container</var> is ''spatial-navigation-action/focus''
     or to <code>true</code> otherwise,
     excluding <var>searchOrigin</var>