+RMR is designed to support different underlying transport mechanisms,
+which might require separate libraries, and thus the library name is
+given a suffix that reflects the transport mechanism in use. RMR
+supports NNG and SI95 as the underlying transports. Nanomsg support
+was dropped starting with version 1.0.45 as Nanomsg has reached end of
+life. The package generation and install will produce two RMR
+libraries: librmr_nng and librmr_si.
+
+NNG version with a commit ID of 906d5ea1b3d67bece941d8a4e0a049e5f6c65051
+is required to build RMR. That version (as yet untagged) adds a
+new error state which we must trap. While application environments
+are encouraged to also build and install at least this version of
+NNG, RMR is still compatable back to the version tagged as 1.1.1.
+If you opt to build with the -DSKIP_EXTERNALS=1 flag set, you must
+ensure that this version of NNG is present in your build environment.
+If you do not set this flag, the proper NNG source will be used
+automatically.
+
+Regardless of transport mechanism supported by an RMR library, the RMR
+API will be identical, thus it is possible for an application to shift
+mechanisms simply by referencing a different library (should multiple
+RMR libraries become available).
+
+Manual Pages
+
+By default the deb created does not include the manual pages. To
+enable their creation, and subsequent inclusion in the deb, add the
+following option to the cmake command:
+
+ -DBUILD_DOC=1
+
+This will cause the {X}fm text formatting package to be fetched
+(github) and built at cmake time (must exist before building) and will
+trigger the generation of the man pages in both postscript and troff
+format. The troff pages are placed into the deb and the postscript
+pages are left in the build directory for the developer to convert to
+PDF, or otherwise use.
+
+Debug Mode
+
+Because RMR is designed to keep its overhead to an absolute minimum,
+messages written to standard error are by default very limited. The
+route table collection thread provides the means to enable debug
+messages on the fly, but only because that thread does not impact the
+sending and receiving of user messages.
+
+If it becomes necessary, for development or problem soving, to have
+the RMR functions generate debugging messages the following
+CMake flag can be given when the CMake environment is created:
+ -DDEBUG=n
+
+The value for 'n' should be 1 or 2 to enable debugging. The default
+when not given is the same as setting n to zero.
+
+When running in debug mode, RMR will log messages received, sent, and
+other useful information. Because debugging uses fprintf() there is a
+significant amount of overhead with logging this information and thus
+in debugging mode the user should not expect that usual message rates
+can be achieved, and in some cases may cause messages to drop if TCP
+queues become full.