The keywords “fixed-major” and “fixed-minor” can be used for tickets that span both a minor and major milestone. A ticket fixed in the major release (and then usually re-opened for minor release consideration) will not show in reports 5 and 6. A ticket fixed in the minor release (and then usually needs more work for a major release) will not show in reports 3 and 4.
The ticket does need to remain open and set to the minor release milestone, so really it’s just a way for committers get it out of sight, out of mind when appropriate. Eventually a ticket tagged fixed-major will either be backported or not (and closed either way), and a ticket tagged fixed-minor should either be dealt with in a timely fashion, or split into two tickets.