Following the documentation at [ 1 ], create the actual release branch at r/a.b.c and announce its existence to the following lists:
email@example.com (developers list)
firstname.lastname@example.org (committers list)
email@example.com (users list)
The corresponding e-mail template can be found on [ 1 ] as well.
The release branch has been created at r/1.5.0 with POM version 1.5.0-SNAPSHOT