Thanks Crizzo for your reply and suggestions!
BUTTON_PM_NEW = New PM
This is for composing a new PM (If I've read the code correct). i.e. for the button to press in order to write a new PM.
POST_NEW_PM = ucp.php file and is for Composing a message (Compose message)
UCP_PM_COMPOSE = Compose a PM (found in ucp.php)
SEND_PRIVATE_MESSAGE = common.php As it says, it is for "Send a private message" (from file: Send private message)
I should have mentioned that English is not my main language, so what I wrote in my OP may have not made much sense.
But I'll try again
When making a new thread, once done, one Post the new thread (Submit works in English).
One make changes to the settings. Once done one Submit the changes (Read: Save settings). It works fine in English, but for it to work in Swedish it
would have been better if Save settings was used (SAVE_SETTINGS).
Write a new PM, post a reply to a PM. One send a PM, or post a reply (or Send can be used if one like).
At the moment Submit is used for these as well.
Hope that makes better sense