A point of order
is a matter raised during consideration of a motion concerning the rules of parliamentary procedure
Parliamentary procedure is the body of rules, ethics, and customs governing meetings and other operations of clubs, organizations, legislative bodies, and other deliberative assemblies...
Explanation and uses
A point of order may be raised if the rules appear to have been broken. This may interrupt a speaker during debate, or anything else if the breach of the rules warrants it. The point is resolved before business continues.
The point of order calls upon the chair to make a ruling. The motion is sometimes erroneously used to ask a question of information or a question of parliamentary procedure. The chair may rule on the point of order or submit it to the judgment of the assembly. If the chair accepts the point of order, it is said to be sustained
or ruled well-taken
. If not, it is said to be overruled
or ruled not well-taken
In organizations other than legislative bodies, the ruling of the chair may be appealed
An appeal is a petition for review of a case that has been decided by a court of law. The petition is made to a higher court for the purpose of overturning the lower court's decision....
to the assembly in most cases. Unless the chair's ruling is overturned by tie or majority vote in the negative, it stands. (The vote that is taken is a vote on whether or not to uphold the decision of the chair, so if the motion fails the decision is overturned.)
Until recently in the British House of Commons
The House of Commons is the lower house of the Parliament of the United Kingdom, which also comprises the Sovereign and the House of Lords . Both Commons and Lords meet in the Palace of Westminster. The Commons is a democratically elected body, consisting of 650 members , who are known as Members...
it was required that a member raising a point of order while the House is voting
In parliamentary procedure, a division of the assembly is a voting method in which the members of the assembly take a rising vote or go to different parts of the chamber, literally dividing into groups indicating a vote in favour of or in opposition to a motion on the floor...
be wearing a hat so they could be easily seen, and two hats were kept in the House for such occasions. This practice has now been abolished. http://news.bbc.co.uk/1/hi/uk_politics/82580.stm
In the United States Senate
The United States Senate is the upper house of the bicameral legislature of the United States, and together with the United States House of Representatives comprises the United States Congress. The composition and powers of the Senate are established in Article One of the U.S. Constitution. Each...
, the chair's ruling may be appealed by any Senator. The Senate votes on the appeal and the chair has been frequently overturned. Points of order with regard to the Budget Act or annual budget resolution may be waived by 3/5 of the Senate's entire membership. Rule XVI, which prohibits normal legislation in appropriations legislation, may be waived by 2/3 of the Senate. 
In the United States House of Representatives
The United States House of Representatives is one of the two Houses of the United States Congress, the bicameral legislature which also includes the Senate.The composition and powers of the House are established in Article One of the Constitution...
tradition, appeals are also possible, but rarely entered and almost never succeed.
In the Irish Oireachtas
The Oireachtas , sometimes referred to as Oireachtas Éireann, is the "national parliament" or legislature of Ireland. The Oireachtas consists of:*The President of Ireland*The two Houses of the Oireachtas :**Dáil Éireann...
(parliament) a point of order is "a submission to the chair in respect of a decision he has not yet taken with a view to influencing that decision by presenting certain facts or arguments." This cannot arise in relation to a decision already taken and must relate to a procedural item in the House or on the Standing Orders. A point of information cannot be raised when the Chair (Ceann Comhairle
The Ceann Comhairle is the chairman of Dáil Éireann, the lower house of the Oireachtas of Ireland. The person who holds the position is elected by members of the Dáil from among their number in the first session after each general election...
Cathaoirleach is the title of the chairman of Seanad Éireann, the sixty-member upper house of the Oireachtas, the legislature of Ireland. The current Cathaoirleach is Senator Paddy Burke...
1) dealing with disorder, 2) putting a question, 3) addressing the House or 4) dealing with an order of the house.
These rules come mainly from precedent and common practice, as there is no provision in the official Standing Orders http://www.oireachtas.ie/documents/proceduralDocuments/STANDING-ORDERS-ENGLISH.pdf
for Points of Order. They are, however, usually dealt with in the standing orders as motions
In parliamentary procedure, a motion is a formal proposal by a member of a deliberative assembly that the assembly take certain action. In a parliament, this is also called a parliamentary motion and includes legislative motions, budgetary motions, supplementary budgetary motions, and petitionary...