[css-page-floats] small language fixes, add definition of not overlapping

Author: johanneswilm

css-page-floats/Overview.bs

@@ -73,9 +73,11 @@ Terminology</h2>
     <dt><dfn>Float reference</dfn>
     <dd>
       The entity to which the float is aligned.
+    <dt><dfn>Not overlapping</dfn></dt>
+      Two elements are not overlapping if the margin box of one element is not
+      overlapping the margin box of the other element.
   </dl>
 
-
 <h2 id="floating">
 Floating to the inline-start/inline-end and block-start/block-end</h2>
 
@@ -794,16 +796,16 @@ img {
 
 <h2 id="page-float-placement">Page float placement</h2>
 
-  The order of page float placement is determined by the following rules:
+  The order of page floats placement is determined by the following rules:
 
   <ol>
     <li>
-      All page floats with 'float-reference' set to `page` are placed, in the
-      order they appear in the DOM, before those with 'float-reference' set to
-      `region` and `column`.
+      All page floats with 'float-reference' set to `page` are placed, in
+      document order, before those with 'float-reference' set to `region` and
+      `column`.
     <li>
       Thereafter, page floats with 'float-reference' set to `column` and `region`
-      are placed in the order they appear in the DOM.
+      are placed in document order.
     </li>
   </ol>
 
@@ -860,15 +862,15 @@ Float references can grow up to the their `max-height` and `max-width` or their
 
 Page floats are stacked within a given <a>float reference</a> in the order of their
 placement and in the direction of the inline- and flow-directions of the
-<a>fragmentation context</a> without overlapping with other page floats with the same
-<a>float reference</a> and by keeping a distance N between the page float's
-margin edge and the padding edge of the <a>float reference</a> as well as between
-the page float's margin edge and the margin edge of the last previously placed page
-float with the same <a>float reference</a> and the same 'float' value, where N is
-the 'float-offset' value of the page float. For the placement it is assumed that
-the page floats in the block directions fill the entire line size of the <a>float
-reference</a> and page floats in the inline direction fill the entire block size
-of the <a>float reference</a>.
+<a>fragmentation context</a> while <a>not overlapping</a> with any other page
+floats with the same <a>float reference</a> and by keeping a distance N between
+the page float's margin edge and the padding edge of the <a>float reference</a>
+as well as between the page float's margin edge and the margin edge of the last
+previously placed page float with the same <a>float reference</a> and the same
+'float' value, where N is the 'float-offset' value of the page float. For the
+placement it is assumed that the page floats in the block directions fill the
+entire line size of the <a>float reference</a> and page floats in the inline
+direction fill the entire block size of the <a>float reference</a>.
 
 If the page float has a defined 'clear'-value, then the <a>float reference</a> in
 which the page float is placed is closed for all subsequent page floats that
@@ -1089,6 +1091,12 @@ p { float-reference: page; float: top; float-defer: last }
   :
 
   <ol>
+    <li>
+      Add term definition for 'not overlapping'.
+    </li>
+    <li>
+      Use term "document order" instead of "order ... appear in the DOM".
+    </li>
     <li>
       Make the order of page float placement determined both by DOM and how high
       in the DOM the page float reference is.