6398 Same name as format
Cause
This error occurs if you attempt to add a TranslatableString with the same name as an existing date, time, number, or currency format. In the following example, an attempt is made to add a translatable string with the name DateFormat using the addCompileTranslatableString method of the Schema class. The attempt fails because there is already a format defined in the schema with the name DateFormat.
currentSchema.addCompileTranslatableString('DateFormat="Hello World"', errCode, errOffset, errLength);
Action
Select a name for the translatable string that is not one of the defined formats for the schema.