[css-display-3] Add definition of absolute positioning to glossary.

Author: fantasai

css-display-3/Overview.bs

@@ -1165,6 +1165,12 @@ Appendix A: Glossary</h2>
 			Note: some [=formatting contexts=] inhibit floating,
 			so that an element with ''float: left'' is not necessarily <a>out-of-flow</a>.
 
+		<dt><dfn lt="absolutely positioned | absolutely positioned element | absolutely positioned box">absolutely posititioned</dfn>
+		<dd>
+			A box is <a>absolutely positioned</a>
+			if its 'position' property is either ''absolute'' or ''fixed''.
+			Absolutely positioned boxes are also <a>out-of-flow</a>.
+
 		<dt><dfn>document order</dfn>
 		<dd>
 			The order in which boxes or content occurs in the document
@@ -1361,6 +1367,22 @@ Acknowledgments</h2>
 <h2 class=no-num id="changes">
 Changes</h2>
 
+	Changes since the <a href="https://www.w3.org/TR/2018/CR-css-display-3-20180828/">28 August 2018 Candidate Recommendation</a>
+	include:
+
+	<ul>
+		<li id="change-parent">
+			Defined <a>parent box</a>.
+		<li id="change-abspos">
+			Added definition of <a>absolutely positioned</a> to the glossary;
+			<a href="https://www.w3.org/TR/CSS2/visuren.html#absolutely-positioned">copied from CSS2</a> for easier referencing.
+		<li id="change-bidi-fragment">
+			Added cross-references to various forms of fragmentation in [[#intro]].
+	</ul>
+
+<h3 id="changes-wd">
+Changes Prior to Candidate Recommendation Status</h3>
+
 	A <a href="https://drafts.csswg.org/css-display-3/issues-wd-2017">Disposition of Comments</a> is available.
 
 	Changes since the <a href="https://www.w3.org/TR/2018/WD-css-display-3-20180420/">20 April 2018 Working Draft</a> include: