--- freem/doc/freem.1	2025/04/03 15:56:41	1.4
+++ freem/doc/freem.1	2025/04/17 15:08:24	1.6
@@ -13,7 +13,7 @@
 .\" To print this man page to a PostScript printer:
 .\"   man -t ./freem.1 | lpr
 .\"
-.\"   $Id: freem.1,v 1.4 2025/04/03 15:56:41 snw Exp $
+.\"   $Id: freem.1,v 1.6 2025/04/17 15:08:24 snw Exp $
 .\"    FreeM man page
 .\"
 .\"  
@@ -38,6 +38,12 @@
 .\"   along with FreeM.  If not, see <https://www.gnu.org/licenses/>.
 .\"
 .\"   $Log: freem.1,v $
+.\"   Revision 1.6  2025/04/17 15:08:24  snw
+.\"   Add documentation on FREEM_LOG_THRESHOLD environment variables to man pages
+.\"
+.\"   Revision 1.5  2025/04/04 12:49:19  snw
+.\"   Dollar signs cut off in ENVIRONMENT sections of both man pages
+.\"
 .\"   Revision 1.4  2025/04/03 15:56:41  snw
 .\"   Add fmadm man page to CVS
 .\"
@@ -121,11 +127,40 @@ freem.conf
 The FreeM configuration file. Normally located in $PREFIX/etc/freem/<environment-name>/freem.conf.
 .SH ENVIRONMENT
 .TP
-\$DISPLAY
+$DISPLAY
 Determines the value of the $PDISPLAY intrinsic special variable. This determines the X11 display used by the M Windowing API. Only applies when FreeM is built with the '--enable-mwapi' configuration option.
 .TP
-\$TERM
+$TERM
 Used by the ^$DEVICE structured system variable to provide the TERMID value for I/O channel 0.
+.TP
+$FREEM_LOG_THRESHOLD_FILE
+Overrides the configured threshold at which log messages are written to files in /var/log/freem, corresponding to the log_threshold_file environment setting in $PREFIX/etc/env.conf. The default value is "info".
+.TP
+$FREEM_LOG_THRESHOLD_SYSLOG
+Overrides the configured threshold at which log messages are sent to the syslog facility on systems that support it, corresponding to the log_threshold_syslog environment setting in $PREFIX/etc/env.conf. The default value is "info".
+.TP
+$FREEM_LOG_THRESHOLD_STDERR
+Overrides the configured threshold at which log messages are sent to stderr, corresponding to the log_threshold_stderr environment setting in $PREFIX/etc/env.conf. The default value is "warning".
+.SH LOG THRESHOLD VALUES
+This section details the valid values for each of the $FREEM_LOG_THRESHOLD_* environment variables, and each value indicates a minimum diagnostic level at which the indicated class of message will be delivered through the selected mechanism. All messages with an equal or higher diagnostic level than the class indicated will be delivered, i.e., if "warning" is selected, messages with a diagnostic class of warning, error, and fatal will be delivered through the selected mechanism.
+
+Valid values for each of these environment variables are as follows:
+.TP
+debug
+Messages useful mostly for developers contributing to FreeM itself. Will produce a high volume of log messages, and is likely to impact system performance. Not recommended for production usage.
+.TP
+info
+Includes messages of an informational nature. Will produce a moderately high volume of log messages. For heavily multi-user and multi-process systems, it is recommended to use "warning" instead.
+.TP
+warning
+Includes warning messages. These indicate conditions (including retries when attempting to acquire semaphores) that warrant further investigation by the system operator, but do not typically prevent applications from running.
+.TP
+error
+Includes error messages. This class of messages indicates that a recoverable error has occurred in the FreeM engine. Warrants immediate attention by the system operator.
+.TP
+fatal
+Includes messages indicating errors that are not recoverable. If this class of message occurs, the process that triggered the message has terminated abnormally. Requires immediate system operator intervention, and can indicate gross misconfiguration of the FreeM engine or the host operating system environment, or even a FreeM bug.
+
 .SH BUGS
 Check the issue tracker at https://bugs.coherent-logic.com for more detailed information on current bugs.
 .SH AUTHOR