+Call only if packets for sending exists. The check of outbound packets
+existence is performed @strong{every} time we are going to make a call,
+but @emph{when-tx-exists} does not influence @emph{cron}. When
+@emph{cron} configuration decides that it is time to make a call, with
+@emph{when-tx-exists} option it checks packets existence first.
+
+@vindex nock
+@anchor{CfgNoCK}
+@item nock
+NoCK (no-checksumming) tells not to do checksumming of received files,
+assuming that it will be done for example with @ref{nncp-check} command
+later. That can help minimizing time spent online, because HDD won't do
+simultaneous reading of the data for checksumming and writing of the
+received one, but just sequential writing of the file. Pay attention
+that you have to make a call to remote node after checksumming is done,
+to send notification about successful packet reception.
+
+@vindex mcd-ignore
+@anchor{CfgMCDIgnore}
+@item mcd-ignore
+Ignore @ref{MCD} announcements: do not add MCD addresses for possible
+connection attempts.