Cosmetics.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

protocol/protocol.tex

@@ -2053,9 +2053,8 @@ ensuring that none of those \transactions can be modified without modifying the
 
 4 & $\nTime$ & \type{uint32\_t} & The \blockTime is a Unix epoch time when the miner
 started hashing the header (according to the miner). This \MUST be greater than or equal
-to the median time of the previous 11 blocks. \todo{has this changed?} A \fullnode
-\MUSTNOT accept \blocks with headers more than two hours in the future according to
-its clock. \\ \hline
+to the median time of the previous 11 blocks. \todo{has this changed?} A \fullnode{} \MUSTNOT
+accept \blocks with headers more than two hours in the future according to its clock. \\ \hline
 
 4 & $\nBits$ & \type{uint32\_t} & An encoded version of the target threshold this \block's
 header hash must be less than or equal to, in the same nBits format used by \Bitcoin. \\ \hline
@@ -2071,7 +2070,7 @@ according to \crossref{equihash}. \\ \hline
 
 The changes relative to \Bitcoin version 4 blocks as described in \cite{blockheaders} are:
 \begin{itemize}
-  \item The \blockVersionNumber \MUST be 4. Previous versions are not supported. Software
+  \item The \blockVersionNumber{} \MUST be 4. Previous versions are not supported. Software
         that parses blocks \MUSTNOT assume, when an encoded \block starts with an $\nVersion$
         field representing a value other than 4 (e.g. future versions potentially introduced
         by hard forks), that it will be parseable according to this format.