Bukkit

You are able to create localization or use the standard which will be enUS. Have a look here for finished localizations.

Located in:plugins\marriage\messages.yml

Important Notes:

You have to leave the <Playername> anywhere in the message example:
In Config: <Playername> accepted your marriage proposal.
In Server: ASC_Dreanor accepted your marriage proposal.

Also for economy the first %s is the price and the second %s is your total balance as an example:
In Config You paid %s and now have %s left.
In Server:You paid 30 coins and now have 20 coins left.

Click here to see the Config.