Edited ch09_fees.adoc with Atlas code editor

ch09_fees.adoc

@@ -27,6 +27,38 @@ that block gets to choose which transactions to include.  Miners may
 select transactions by any criteria they want, including refusing to
 include any transactions at all.
 
+++++
+<div data-type="note">
+<p> When we say "transactions" in this chapter, we refer to every
+transaction in a block except for the first transaction.  The first
+transaction in a block is a <em>coinbase transaction</em>, described in
+<a data-type="xref" href="#coinbase_transactions">#coinbase_transactions</a>, which allows the miner of the block to
+collect their reward for producing the block.  Unlike other
+transactions, a coinbase transaction doesn't spend the output of a
+previous transaction and is also an exception to several other rules
+that apply to other transactions.  Coinbase transactions don't pay
+transaction fees, don't need to be fee bumped, aren't subject to
+transaction pinning, and are largely uninteresting to the following
+discussion about fees--so we're going to ignore them in this [.keep-together]#chapter.
+</p>
+</div>
+++++
+
+[NOTE]
+====
+When we((("transactions", "coinbase")))((("coinbase transactions"))) say "transactions" in this chapter, we refer to every
+transaction in a block except for the first transaction.  The first
+transaction in a block is a _coinbase transaction_, described in
+<<coinbase_transactions>>, which allows the miner of the block to
+collect their reward for producing the block.  Unlike other
+transactions, a coinbase transaction doesn't spend the output of a
+previous transaction and is also an exception to several other rules
+that apply to other transactions.  Coinbase transactions don't pay
+transaction fees, don't need to be fee bumped, aren't subject to
+transaction pinning, and are largely uninteresting to the following
+discussion about fees--so we're going to ignore them in this [.keep-together]#chapter.#
+====
+
 [NOTE]
 ====
 When we((("transactions", "coinbase")))((("coinbase transactions"))) say "transactions" in this chapter, we refer to every