doc: better notes

Author: c-dilks

docs/dev_notes.md

@@ -2,24 +2,32 @@
 
 ## Controlling Log Levels
 
-To control the log level of a class with a `Logger`, make a logging `.properties` file, and set the level of each of your classes for which you want to use a non-default level; use the property name `className.level`, for example:
+To control the log level of a class with a `Logger`, use properties. As CLI options, you may use, for example,
+```
+-Dorg.jlab.detector.helicity.HelicityGenerator.level=FINEST   # sets HelicityGenerator level to FINEST
+-D.level=FINE   # sets the level of all loggers to FINE
+```
+
+Alternatively, make a logging `.properties` file, and set the level of each of your classes for which you want to use a non-default level; use the property name `className.level`, for example:
 ```
 # my_levels.properties
 org.jlab.detector.helicity.HelicityGenerator.level = FINEST
 org.jlab.detector.calib.utils.RCDBProvider.level = FINER
 ```
-You can also control the _global_ log level for all classes with `.level`, for example, to set
-it to `FINE`:
+or use `.level` for the global level:
 ```
+# my_levels.properties
 .level = FINE
 ```
 To use this `.properties` file, run with the `java` option
 ```
 -Djava.util.logging.config.file=my_levels.properties
 ```
-For example, if using `run-coatjava`,
+Then, here are some examples for using it with `recon-util`:
 ```bash
-run-coatjava [CLASS_NAME] [CLASS_ARGS] -- -Djava.util.logging.config.file=my_levels.properties
+recon-util [ARGS] -- -Djava.util.logging.config.file=my_levels.properties   # use your .properties file
+recon-util [ARGS] -- -D.level=ALL   # set the global level to ALL (very verbose!)
+recon-util [ARGS] -- -D.level=OFF   # silence the loggers
 ```
 From high to low, the levels are `SEVERE, WARNING, INFO, CONFIG, FINE, FINER, FINEST` (see `java.util.logging.Level` documentation).
 You may also use levels `ALL` or `OFF`, for everything or nothing, respectively.