Add clarification about logged content.

2 files changed, 4 insertions, 0 deletions

diff --git a/docs/man/nng_log.3.adoc b/docs/man/nng_log.3.adoc
index 852f765b..358264c2 100644
--- a/docs/man/nng_log.3.adoc
+++ b/docs/man/nng_log.3.adoc
@@ -55,6 +55,9 @@ The severity can be one of the following values:
 The message itself is handled according to the logging facility set up with xref:nng_mg_set_logger.3.adoc[`nng_log_set_logger`].
 Message delivery is best effort, and messages may be suppressed based on the priority set with xref:nng_log_set_level.3.adoc[`nng_log_set_level`].
 
+Note that in order to get log messages, a suitable logger must be set using `nng_log_set_logger`.
+The default logger, `nng_null_logger` simply discards logged content.
+
 == SEE ALSO
 
 xref:nng_log_set_facility.3.adoc[nng_log_set_facility(3)],
diff --git a/docs/man/nng_log_set_logger.adoc b/docs/man/nng_log_set_logger.adoc
index 4f3cafc8..eedbca49 100644
--- a/docs/man/nng_log_set_logger.adoc
+++ b/docs/man/nng_log_set_logger.adoc
@@ -36,6 +36,7 @@ Only a single logger may be registered at a time.
 If needed, the logger should make copies of either _msgid_ or _msg_, as those may not be valid once the logger function returns.
 
 The `nng_null_logger` function is an implementation of `nng_logger` that simply discards the content.
+This is the default logger, so logging is disabled by default.
 
 The `nng_stderr_logger` function is an implementation that logs messages to the standard error stream.
 It will attempt to colorize messages by the severity, if the standard error is a terminal device.