diff --git a/doc/draft-ietf-codec-oggopus.xml b/doc/draft-ietf-codec-oggopus.xml
index 9f073c9..db4542d 100644
--- a/doc/draft-ietf-codec-oggopus.xml
+++ b/doc/draft-ietf-codec-oggopus.xml
@@ -11,7 +11,7 @@
 ]>
 <?rfc toc="yes" symrefs="yes" ?>
 
-<rfc ipr="trust200902" category="std" docName="draft-ietf-codec-oggopus-03">
+<rfc ipr="trust200902" category="std" docName="draft-ietf-codec-oggopus-04">
 
 <front>
 <title abbrev="Ogg Opus">Ogg Encapsulation for the Opus Audio Codec</title>
@@ -60,7 +60,7 @@
 </address>
 </author>
 
-<date day="7" month="February" year="2014"/>
+<date day="9" month="August" year="2014"/>
 <area>RAI</area>
 <workgroup>codec</workgroup>
 
@@ -365,7 +365,7 @@
  the number of samples which SHOULD be skipped (decoded but discarded) at the
  beginning of the stream.
 This amount MAY not be a multiple of 2.5&nbsp;ms, MAY be smaller than a single
- packet, or MAT span the contents of several packets.
+ packet, or MAY span the contents of several packets.
 These samples are not valid audio, and should not be played.
 </t>
 
@@ -702,7 +702,7 @@
  inaudible sounds to the threshold of physical pain), most applications can
  only reasonably use a small portion of this range around zero.
 The large range serves in part to ensure that gain can always be losslessly
- transferred between OpusHead and R128_TRACK_GAIN (see below) without
+ transferred between OpusHead and R128 gain tags (see below) without
  saturating.
 <vspace blankLines="1"/>
 </t>
@@ -1173,7 +1173,7 @@
  ARTIST, TITLE, DATE, ALBUM, and so on.
 </t>
 <t>
-Two new comment tags are introduced for Ogg Opus:
+Two new comment tags are introduced here:
 </t>
 
 <figure align="center">
@@ -1200,7 +1200,7 @@
 ]]></artwork>
 <postamble>
 representing the volume shift needed to normalize the overall volume when
- played as part of a collection of tracks.
+ played as part of a particular collection of tracks.
 The gain is also a Q7.8 fixed point number in dB, as in the ID header's
  'output gain' field.
 </postamble>
@@ -1229,10 +1229,10 @@
 To avoid confusion with multiple normalization schemes, an Opus comment header
  SHOULD NOT contain any of the REPLAYGAIN_TRACK_GAIN, REPLAYGAIN_TRACK_PEAK,
  REPLAYGAIN_ALBUM_GAIN, or REPLAYGAIN_ALBUM_PEAK tags.
-The <xref target="EBU-R128"/> normalization is preferred to the earlier
+<xref target="EBU-R128"/> normalization is preferred to the earlier
  REPLAYGAIN schemes because of its clear definition and adoption by industry.
-PEAK normalizations are difficult to calculate reliably because of variation
- in excursion heights due to decoder differences.
+PEAK normalizations are difficult to calculate reliably for lossy codecs
+ because of variation in excursion heights due to decoder differences.
 In the authors' investigations they were not applied consistently or broadly
  enough to merit inclusion here.
 </t>
@@ -1243,7 +1243,7 @@
 
 <section anchor="packet_size_limits" title="Packet Size Limits">
 <t>
-Technically valid Opus packets can be arbitrarily large due to the padding
+Technically, valid Opus packets can be arbitrarily large due to the padding
  format, although the amount of non-padding data they can contain is bounded.
 These packets might be spread over a similarly enormous number of Ogg pages.
 Encoders SHOULD use no more padding than required to make a variable bitrate