standard way to use shortcuts in l10n

Hello, Is there any standard for using shortcuts while l10n-ing? Should I put shorcuts in localize form? or keep same english short cut separately in parenthesis? like, for msgid "_File" Should I use, msgstr "_xx" or msgstr "xx (_x)" or msgstr "xx (_F)" <--- this _F will be taken from the msgid's shorcut xx will be written in my localized character. Waiting for your valued reply! Thanks, `Jamil L10n: Bengali