Masonic lodges have a variety of rituals and ceremonies that differ from jurisdiction to jurisdiction. The largest Masonic organization, the United Grand Lodge of England, has around a quarter of a million members. During the initiation process, candidates are taught the meanings of Masonic symbols and are given signs and words to identify themselves as Masons. Private lodges have the exclusive right to choose their own candidates for initiation and sometimes have exclusive rights over their facilities.
The Grand Lodge approved several changes between 1730 and 1750 that some lodges were unable to accept. Each lodge follows ancient principles known as the landmarks of Freemasonry, which are not universally defined. Freemasonry is not a religion or a substitute for religion, but Masons and their charities contribute to many fields such as education, health, and old age. Freemasonry spread from France and England to most of continental Europe in the 18th century.
There is no international Grand Lodge that oversees all Masonry; each Grand Lodge is independent and does not necessarily recognize each other as legitimate. Critics include religious groups, political groups, and conspiracy theorists who defend Masonic conspiracy theories or Judeo-Masonic conspiracy theory. The three degrees of Freemasonry preserve the three degrees of the medieval artisan guilds: apprentice, officer or companion (now called Fellowcraft), and master Mason. The small blue flower “don't forget me” was first used by the Grand Lodge Zur Sonne in 1926 as a Masonic emblem at the annual convention in Bremen (Germany).
Certain Christian denominations have shown negative attitudes towards Freemasonry, prohibiting or discouraging their members from being Masons.