Looking through ^/subversion/branches, I found that there are many backport branches that are not mentioned in any STATUS file. After consulting 'svn mergeinfo' and log, I found that the ones listed below can be removed.
The list names the branch "owners" and the reason why those branches are obsolete. If nobody objects, I'll remove them around the 15th this month. -- Stefan^2. 1.8.x Brane: 1.8.x-javahl-exception-crash (fully merged into 1.8.x) Philip: 1.8.x-r1577812 (fully merged into 1.8.x) Julian: 1.8.x-r1619380 (not modified) 1.7.x StSp: 1.7.x-issue3741 (fully merged, directly from /trunk) Philip: 1.7.x-issue4091 (fully merged, directly from /trunk) Bert: 1.7.x-issue-4295 (not modified) Julian: 1.7.x-r1594156 (not modified) Bert: 1.7.x-commit-performance (not merged, withdrawn from STATUS) Daniel: 1.7.x-fs-verify (not merged, withdrawn from STATUS) Neels: 1.7.x-i4016 (not merged, superseded by a smaller patch, never mentioned in STATUS) StSp: 1.7.x-r1195873 (not merged, never mentioned in STATUS) Bert: 1.7.x-r1557094 (not merged, vetoed, later removed from STATUS) 1.6.x Blair: 1.6.x-r1051744 (fully merged into 1.6.x) Daniel: 1.6.x-r1053984 (fully merged into 1.6.x) Paul: 1.6.x-r878590 (fully merged into 1.6.x) Stylesen: 1.6.x-r39692 (not merged, vetoed, later removed from STATUS) Paul: 1.6.x-issue3657 (not merged, never mentioned in STATUS)