diff --git a/protocol/protocol.tex b/protocol/protocol.tex
index 27f55038..ee8e720b 100644
--- a/protocol/protocol.tex
+++ b/protocol/protocol.tex
@@ -663,6 +663,7 @@ electronic commerce and payment, financial privacy, proof of work, zero knowledg
 \newcommand{\Mimblewimble}{\termbf{Mimblewimble}}
 \newcommand{\Bulletproofs}{\termbf{Bulletproofs}}
 \newcommand{\ZEC}{\termbf{ZEC}}
+\newcommand{\TAZ}{\termbf{TAZ}}
 \newcommand{\zatoshi}{\term{zatoshi}}
 \newcommand{\zcashd}{\termsf{zcashd}}
 \newcommand{\Makefile}{\texttt{Makefile}\xspace}
@@ -834,10 +835,16 @@ electronic commerce and payment, financial privacy, proof of work, zero knowledg
 \newcommand{\fullValidators}{\terms{full validator}}
 \newcommand{\consensusRuleChange}{\term{consensus rule change}}
 \newcommand{\networkUpgrade}{\term{network upgrade}}
+\newcommand{\networkUpgrades}{\terms{network upgrade}}
+\newcommand{\Mainnet}{\term{Mainnet}}
+\newcommand{\Testnet}{\term{Testnet}}
+\newcommand{\rpcByteOrder}{\term{RPC byte order}}
 \newcommand{\anchor}{\term{anchor}}
 \newcommand{\anchors}{\terms{anchor}}
 \newcommand{\block}{\term{block}}
 \newcommand{\blocks}{\terms{block}}
+\newcommand{\blockHash}{\term{block hash}}
+\newcommand{\blockHashes}{\termes{block hash}}
 \newcommand{\header}{\termandindex{header}{block header}}
 \newcommand{\headers}{\termandindex{headers}{block header}}
 \newcommand{\blockHeader}{\term{block header}}
@@ -850,6 +857,7 @@ electronic commerce and payment, financial privacy, proof of work, zero knowledg
 \newcommand{\blockTimestamp}{\term{block timestamp}}
 \newcommand{\blockHeight}{\term{block height}}
 \newcommand{\blockHeights}{\terms{block height}}
+\newcommand{\activationBlock}{\term{activation block}}
 \newcommand{\activationHeight}{\term{activation block height}}
 \newcommand{\activationHeights}{\terms{activation block height}}
 \newcommand{\genesisBlock}{\term{genesis block}}
@@ -3122,6 +3130,36 @@ included in this \block. The \coinbaseTransaction{} \MUST also pay the \founders
 as described in \crossref{foundersreward}.
 
 
+\lsubsection{Mainnet and Testnet}{networks}
+
+The production \Zcash network, which supports the \ZEC token, is called \Mainnet. Governance of its
+protocol is by agreement between the Electric Coin Company and the Zcash Foundation \cite{ECCZF2019}.
+Subject to errors and omissions, each version of this document intends to describe some version
+(or planned version) of that agreed protocol.
+
+\defining{All \blockHashes given in this section are in \rpcByteOrder \cite{Bitcoin-Order}.}
+
+\Mainnet \genesisBlock: $\mathtt{00040fe8ec8471911baa1db1266ea15dd06b4a8a5c453883c000b031973dce08}$
+
+\Mainnet \Blossom \activationBlock: $\mathtt{00000000020bebb33c1b34b67a982a328ab212a206dacbe561a7cc94aab3e9bb}$
+
+There is also a public test network called \Testnet. It supports a \TAZ token which is intended to
+have no monetary value. By convention, \Testnet activates \networkUpgrades (as described in
+\crossref{networkupgrades}) before \Mainnet, in order to allow for errors or ambiguities in
+their specification and implementation to be discovered. The \Testnet \blockChain is subject to
+being rolled back to a prior \block at any time.
+
+\Testnet \genesisBlock: $\mathtt{05a60a92d99d85997cce3b87616c089f6124d7342af37106edc76126334a2c38}$
+
+\Testnet \Heartwood \activationBlock: $\mathtt{05688d8a0e9ff7c04f6f05e6d695dc5ab43b9c4803342d77ae360b2b27d2468e}$
+
+We call the smallest units of currency (on either network) \zatoshi.
+
+On \Mainnet, $1$ \ZEC = $10^8$ \zatoshi. On \Testnet, $1$ \TAZ = $10^8$ \zatoshi.
+
+Other networks using variants of the \Zcash protocol may exist, but are not described by this specification.
+
+
 \intropart
 \lsection{Abstract Protocol}{abstractprotocol}
 
@@ -8725,7 +8763,7 @@ and in the multi-party computation to obtain the \Sapling parameters given in
 It is derived as described in \cite{Bowe2018}:
 
 \begin{itemize}
-  \item Take the hash of the \Bitcoin \block at height $514200$ in RPC byte order \cite{Bitcoin-Order},
+  \item Take the hash of the \Bitcoin \block at height $514200$ in \rpcByteOrder \cite{Bitcoin-Order},
         i.e.\ the big-endian $32$-byte representation of $\hexint{00000000000000000034b33e842ac1c50456abe5fa92b60f6b3dfc5d247f7b58}$.
   \item Apply \shaHash $2^{42}$ times.
   \item Convert to a US-ASCII lowercase hexadecimal string.
@@ -8736,7 +8774,6 @@ It is derived as described in \cite{Bowe2018}:
 } %sapling
 
 
-\notsprout{
 \intropart
 \lsection{Network Upgrades}{networkupgrades}
 
@@ -8811,7 +8848,6 @@ validated according to the pre-upgrade rules, and
 upgrade-supporting nodes \MUST allow for this.
 
 %\todo{how upgrade-dependent rules are described in this specification.}
-} %notsprout
 
 
 \intropart
@@ -10522,8 +10558,9 @@ Peter Newell's illustration of the Jubjub bird, from \cite{Carroll1902}.
 \intropart
 \lsection{Change History}{changehistory}
 
-\historyentry{2020.1.9}{}
+\historyentry{2020.1.9}{2020-07-05}
 \begin{itemize}
+    \item Add \crossref{networks}.
     \item Acknowledge Jane Lusby and Teor.
 \sapling{
     \item Correct an error introduced in 2020.1.8; ``$-\ZeroJ$'' was incorrectly used when
diff --git a/protocol/zcash.bib b/protocol/zcash.bib
index a6de69a6..11cdafeb 100644
--- a/protocol/zcash.bib
+++ b/protocol/zcash.bib
@@ -1416,3 +1416,12 @@ Proceedings of the 19th Annual International Cryptology Conference
    url={https://electriccoin.co/blog/zcash-counterfeiting-vulnerability-successfully-remediated/},
    urldate={2019-08-27}
 }
+
+@misc{ECCZF2019,
+  presort={ECCZF2019},
+  author={Electric Coin Company and Zcash Foundation},
+  title={Zcash {T}rademark {D}onation and {L}icense {A}greement},
+  date={2019-11-06},
+  url={https://www.zfnd.org/about/contracts/2019_ECC_ZFND_TM_agreement.pdf},
+  urldate={2020-07-05}
+}