of the Exclusive Brethren, but are rather a very conservative subset of the Open Brethren. The Gospel Halls regard reception to the assembly as a serious matter. One is not received to the Lord's Supper but to the fellowship of the assembly. This is important because the Lord's Supper is for believers, not unbelievers. Some chapels, on the other hand, will allow practically anyone to participate who walks in and says that he is a Christian, based on the newcomer's profession of faith. Such assemblies are said to have an "open table" approach to strangers. Gospel Hall Brethren, on the other hand, generally believe that only those formally recognised as part of that or an equivalent assembly should break bread. Most Closed and some Open Brethren hold that association with evil defiles and that sharing the Communion meal can bring that association. Their support text is from 1 Corinthians 15:33, "Do not be deceived: evil communications corrupt good manners." Among other distinctions, the Gospel Halls would generally not use musical instruments in their services, whereas many Chapels use them and may have singing groups, choirs, "worship teams" of musicians, etc. The Gospel Halls tend to be more conservative in dress; women do not wear trousers often, although they can and there is no scriptural objection in doing so, but most do not wear them in meetings and always have their heads covered, while in most Chapels women may wear whatever they wish, though modesty in dress serves as a guideline, and many continue the tradition of wearing a head covering taught in 1 Corinthians 11:2-13. Open Brethren churches are all independent, self-governing, local congregations with no central headquarters, although there are a number of seminaries, missions agencies, and publications that are widely supported by Brethren churches and which help to maintain a high degree of communication among them. Henry K. Carroll performed an analysis of United States census data in 1912 to assign Roman numerals to various Brethren groups. For example, Brethren III is also known as the Lowe Brethren and the Elberfeld Brethren. Carroll's initial findings listed four sub-groups, identified as Brethren I-IV, but he expanded the number to six and then to eight; Arthur Carl Piepkorn expanded the number to ten. Those who have attempted to trace the realignments of the Plymouth Brethren include Ian McDowell and Massimo Introvigne. The complexity of the Brethren's history is evident in