I came across a problem where the copyright pop up message during logon is appearing as English with logon in Chinese language.
After investing lot of time, found below way to translate those texts.
These entries are stored in Cluster Table "DOKTL". Based on the contents identify the documentation object from table "DOKTL".
Documentation object in this case is "COPYRIGHT_ORACLE". Now to translate these entries go to transaction SE63.
Go to ABAP Objects --> Long texts (Documentation) --> C6 F1 Help --> TX General Texts
Enter object name as below.
Translate the text as shown below --> Save --> Activate.
Now Login with ZH language, you will find the pop up message as translated above.