R.S.V.P literally translates to the French phrase “répondez, s’il vous plaît”. This means please reply. The conventions of etiquette which are noticeably influenced by the French has dictated that once a person receives an R.S.V.P in the form of an invitation he or she should do the polite thing and respond. The simple logic behind the R.S.V.P phenomenon is this: if you are invited to a function then you should state whether you will attend or not. To some this may seem petty however there is certainly much sense in condoning the use of an R.S.V.P with most standard invitations.
For example when a wedding is being planned and the invitations are sent out, perhaps months in advance, an R.S.V.P note will be placed on each invitation. When most people plan a wedding the expenses are established in such a way that they may pay the caterers or hotel per plate of food. Hence when people are tardy in replying or do not reply at all they often have to over estimate the number of people they expect which will undoubtedly be less cost effective. For this reason most people prefer to know how many people will attend a few weeks in advance. This principle thus applies to other types of functions where arrangements must be made for factors such as seating and food.
The appropriate way to respond to an R.S.V.P is of critical importance especially for functions that may be of a more professional inclination. If you are mailed an invitation by post you should respond in the same fashion. This means you should compose a letter that may either be written legibly (if it is a response to a close association) or typed and addressed professionally for more formal invitations. It is not considered very polite to call a person who has taken the time to send you an invitation by mail. Though there are some people that will overlook this blunder it is perhaps best to act in accordance with social conventions. If you cannot attend do not forget to apologize and perhaps give a brief but plausible explanation for your inability to be present. It may be as simple as saying you had a previous engagement or that you will be out of the country. However ensure that your words invoke sincerity and some amount of regret. If you are sent an email invite with an attached R.S.V.P note you may send an email in response to the original invitation. This email should be well written and should include standard letter opening and closing.
Although to some people it may not seem a necessity to respond, it is still best that you make the effort to acknowledge an R.S.V.P. It lets the other person know that you are not only polite and well mannered but that you respect them enough to take the extra time needed to reply to a simple invitation. If you are not a stickler for politeness then consider the more logical argument of allowing your host or hostess to know in advance how many guests to expect.