Anytime you see something like %M or %1 - that is a variable. A variable is something that the client will insert at that point - substituting the variable name for the real value. Sometimes it is preceded by a backslash (\)...if it's there in the original, it needs to be there in the translation.
For date fields there is %m (month) %d (day) and %y (year). For the United States, the format is \%m/\%d/\%y. This will turned to something like 02/05/2010.
For time fields there is %H (hour) and %M (minutes). This will display the time in 24-hour format like: 22:10.
Finally, some fields have a %1 or a %2. These can stand for anything but are typically used to display avatar names or age names.
There is a field called "Possessive" which for English has "%1s's %2s". If %1 is "OHB" and %2 is "Relto" we will get "OHB's Relto". But each language is different. For example, I translated this to Spanish as "%2 de %1" (Relto of OHB).
If you need help with this, just ask!