Editorial: add note that Request's signal is always initialized

Author: TimvdLippe

fetch.bs

@@ -8769,7 +8769,7 @@ constructor steps are:
  <li><p>Let <var>signals</var> be « <var>signal</var> » if <var>signal</var> is non-null; otherwise
  « ».
 
- <li><p>Set <a>this</a>'s <a for=Request>signal</a> to the result of
+ <li id="signal-initialized-in-constructor"><p>Set <a>this</a>'s <a for=Request>signal</a> to the result of
  <a>creating a dependent abort signal</a> from <var>signals</var>, using {{AbortSignal}} and
  <a>this</a>'s <a>relevant realm</a>.
 
@@ -8940,6 +8940,10 @@ set; otherwise false.
 <p>The <dfn attribute for=Request><code>signal</code></dfn> getter steps are to return <a>this</a>'s
 <a for="Request">signal</a>.
 
+<p class="note"><a>This</a>'s <a for="Request">signal</a> is always initialized in the
+<a href="#signal-initialized-in-constructor">constructor</a> and when
+<a href="#signal-initialized-when-cloning">cloning</a>.
+
 <p>The <dfn attribute for=Request><code>duplex</code></dfn> getter steps are to return
 "<code>half</code>".
 
@@ -8956,7 +8960,7 @@ set; otherwise false.
 
  <li><p><a for=/>Assert</a>: <a>this</a>'s <a for=Request>signal</a> is non-null.
 
- <li><p>Let <var>clonedSignal</var> be the result of <a>creating a dependent abort signal</a> from
+ <li id="signal-initialized-when-cloning"><p>Let <var>clonedSignal</var> be the result of <a>creating a dependent abort signal</a> from
  « <a>this</a>'s <a for=Request>signal</a> », using {{AbortSignal}} and <a>this</a>'s
  <a>relevant realm</a>.