Where can we find a field lists and language translation dictionary of SAP By design API?

Let us know how to find or extract a field list and language translation dictionary of ByD API?
ex) of ByD API : QuerySalesOrderIn

Or how to find or extract a field list it shows the mapping between API fields and data source fields.

I beleive this is just spec so we can get it easily...

Back Ground :
I need to arrenge a field list of ByD API for Interface field mapping.
Customer system which is a target of data linkage is based on local language (Japanese).
We need to map fields of customer sysytem to ByD API field in Japanese.
Customer will review the mappping result in Japanese.
So we need to arrenage fields mapping document in Japanese.