diff --git a/doc/of-spec/appendix.tex b/doc/of-spec/appendix.tex
index 8c79b5b..ffac6bb 100755
--- a/doc/of-spec/appendix.tex
+++ b/doc/of-spec/appendix.tex
@@ -152,7 +152,7 @@ The \verb|n_tables| field describes the number of tables supported by the switch
 The \verb|capabilities| field uses the following flags:
 
 \input{enum/ofp_capabilities} 
-The \verb|actions| field is a bitmap of supported actions on the hardware.  It uses the values from \verb|ofp_action_type| as the number of bits to shift left for an associated action.  For example, \verb|OFPAT_SET_DL_VLAN| would use the flag \verb|0x00000002|.
+The \verb|actions| field is a bitmap of actions supported by the switch.  The list of actions is found in Section~\ref{ft:actions}; all actions marked Required must be supported. Vendor actions should \emph{not} be reported via this bitmask. The bitmask uses the values from \verb|ofp_action_type| as the number of bits to shift left for an associated action. For example, \verb|OFPAT_SET_DL_VLAN| would use the flag \verb|0x00000002|.
 \\\\
 The \verb|ports| field is an array of \verb|ofp_phy_port| structures that describe all the physical ports in the system that support OpenFlow.  The number of port elements is inferred from the length field in the OpenFlow header.