The dbbinary command is specified in the manual page for g_qa as the means for reading in a file to an opaque binary object in mged. However, under 1.14.1 the "dbbinary" command does not exist in mged any more.
The "binary" command was renamed "bo" in August 2008 to avoid a name conflict with Tcl's "binary" command. The latest manpage specifies the "bo" command for creating the _DENSITIES object.
This issue has been resolved in the latest (unreleased) version of the source code. Thank you for bringing the issue to our attention! You're welcome and encouraged to test and make sure this issue is resolved after the next source release of BRL-CAD.