I finally understand the cause. Those translations are copied from IBM branches to master branches.
The copy action is trigged by the update of pot files. There are Jenkins jobs automatically uploading pot files by CLI when there are changes. This caused the translations copied from IBM branches to master.
Refer to Zanata help document[1], it is said: Copy Trans usually runs automatically when a document is uploaded using the cli-client.
While I did test on the test server ( http://translate-dev.openstack.org ), there was no such auto jobs running for test server, so I didn't recognize uploading of pot files could cause the copy action. I apologize for missing this point.
What we should do now is to figure out how to handle the situation.
Best regards Ying Chun Guo (Daisy)
[1] http://docs.zanata.org/en/latest/user-guide/translation-reuse/copy-trans/
Hi Daisy, Thank you for detailed investigation. This is not a problem. No need apolpgize. Just need a little more action. Let's hurry coordinator's review. Regards, KATO Tomoyuki