The java.net.HttpClient default configuration can be altered by specifying different JDK implementation specific system properties on the Java command line. Some of them are generally useful and worth being documented in module-info.java,

At the moment the only documentation provided is from the Java Core Libraries Developer Guide [1].

The properties documented in this guide should also be documented in the java.net.http module-info [2]. Whether some documentation should also be added to net-properties.html [3] (possibly just a link to the module-info?) should also be considered.
 
[1] https://docs.oracle.com/en/java/javase/19/core/java-networking.html#GUID-86B96A42-74FE-4E7D-8E60-D64A03862083
[2] https://github.com/openjdk/jdk/blob/master/src/java.net.http/share/classes/module-info.java
[3] https://github.com/openjdk/jdk/blob/master/src/java.base/share/classes/java/net/doc-files/net-properties.html