Tweak some headings, IDs, and intros

index.bs

@@ -620,7 +620,7 @@ href="https://github.com/whatwg/streams/issues/97">#97</a> for more information.
   </code></pre>
 </div>
 
-<h3 id="rs-abstract-ops">Readable Stream Abstract Operations</h3>
+<h3 id="rs-abstract-ops">General Readable Stream Abstract Operations</h3>
 
 <h4 id="acquire-readable-stream-byob-reader" aoid="AcquireReadableStreamBYOBReader" throws>AcquireReadableStreamBYOBReader ( stream )</h4>
 
@@ -940,7 +940,7 @@ an assert).
 
 <h3 id="default-reader-class">Class <code>ReadableStreamDefaultReader</code></h3>
 
-The <code>ReadableStreamDefaultReader</code> class represents a <a>readable stream reader</a> designed to be vended by a
+The <code>ReadableStreamDefaultReader</code> class represents a <a>default reader</a> designed to be vended by a
 <code>ReadableStream</code> instance.
 
 <h4 id="default-reader-class-definition">Class Definition</h4>
@@ -1210,7 +1210,7 @@ Instances of <code>ReadableStreamBYOBReader</code> are created with the internal
   1. Perform ReadableStreamReaderGenericRelease(*this*).
 </emu-alg>
 
-<h3 id="rs-reader-abstract-ops">Readable Stream Reader and BYOB Reader Abstract Operations</h3>
+<h3 id="rs-reader-abstract-ops">Readable Stream Reader Abstract Operations</h3>
 
 <h4 id="readable-stream-reader-generic-initialize" aoid="ReadableStreamReaderGenericInitialize" nothrow>ReadableStreamReaderGenericInitialize ( reader, stream )</h4>
 
@@ -1291,9 +1291,10 @@ Instances of <code>ReadableStreamBYOBReader</code> are created with the internal
 
 <h3 id="rs-default-controller-class" lt="ReadableStreamDefaultController">Class <code>ReadableStreamDefaultController</code></h3>
 
-The <code>ReadableStreamDefaultController</code> class has methods that allow control of a <code>ReadableStream</code>'s state
-and <a>internal queue</a>. When constructing a <code>ReadableStream</code>, the <a>underlying source</a> is given a
-corresponding <code>ReadableStreamDefaultController</code> instance to manipulate.
+The <code>ReadableStreamDefaultController</code> class has methods that allow control of a <code>ReadableStream</code>'s
+state and <a>internal queue</a>. When constructing a <code>ReadableStream</code> that is not a <a>readable byte
+stream</a>, the <a>underlying source</a> is given a corresponding <code>ReadableStreamDefaultController</code> instance
+to manipulate.
 
 <h4 id="rs-default-controller-class-definition">Class Definition</h4>
 
@@ -1487,7 +1488,7 @@ Instances of <code>ReadableStreamDefaultController</code> are created with the i
   1. Return _pendingPromise_.
 </emu-alg>
 
-<h3 id="rs-abstract-ops">Readable Stream Controller Abstract Operations</h3>
+<h3 id="rs-default-controller-abstract-ops">Readable Stream Default Controller Abstract Operations</h3>
 
 <h4 id="is-readable-stream-default-controller" aoid="IsReadableStreamDefaultController" nothrow>IsReadableStreamDefaultController ( x )</h4>