Number of attachments :
The page http://maven.apache.org/guides/plugin/guide-java-plugin-development.html has a small entry under "shortening the command line" which says that artifactId patterns maven-$name-plugin and $name-maven-plugin are treated specially (by convention).
The email of Sep 27, 2008 to maven users list, from Stephen Connolly says
AFAIK only plugins with the groupId org.apache.maven.plugins are allowed to
use the maven-______-plugin pattern. I could not find this documented (other than on the users email list.).
says that the conventional mappings only happen for the "maven-$name-plugin" style, and don't mention the other style ($name-maven-plugin).
I recommend using the text from the 1st ref (which seems to be the clearest) as a starting point, to augment and expand the text in the 3rd ref.
The Complete Reference book is missing this information, as well, I believe.