Partial lists of South Asia communities can be found in medieval sources. After 1806 the British began constructing detailed lists of communities. The 1872 census was the first comprehensive census for the whole of British India. The census gathered data on age, community (with caste as a subheading), occupation, religion, and education levels. There have been decadal censuses conducted consistently since 1872.
The census of 1931 was the last British administered census, and was the last to include headcounts of all classes of society. This census serves as a baseline for all later studies and reports.
The Anthropological Survey of India began a large study of the people of India in 1985. They initially identified more than 6,000 communities, but after further study reduced this count to something over 4,700 communities. However, their list of Main Communities includes only roughly 2,600 entries. Many of these main communities are divided into subgroups, and by state, resulting in an expanded list of more than 4,700 "communities".
The Bania are an example of a South Asia community. The Bania are also part of the formal caste system.
Omid was challenged by Luis Bush in 1996-1997 to create a list of several hundred of the largest communities in India, for an upcoming conference. Omid scrambled to create this list, and it was published (the "Blue Book") by the India Missions Association in 1997. Omid has remarked several times he regretted this list entered into circulation, as he considered it to be incomplete and contained many errors. But he was trying to meet a deadline.
Omid has continued to expand and refine his list since the 1997 list was created. His current list corrects the errors in the earlier list, and is complete to the district level for India, Nepal, Bangladesh, Pakistan, Bhutan, and Myanmar.
The ASI list and the Omid list for India compare reasonably well if a person comes to a good understanding of the data. The main differences come back to how subdividing and grouping is done. But the core list of communities is much the same. The other thing making it difficult to compare is each community typically has several names, depending on where they live in the country. Alternate names often have to be taken into account as the lists are compared. ASI and Omid have been cross-referenced successfully for very close to 100% of the communities.
Advantages of the Omid list relative to the ASI list include the fact Omid is complete to the district level, while ASI goes only to the state level. Omid includes all languages spoken in each district by each community, with numbers of speakers for each language, and with numbers of Muslims, Hindus, etc. by language, by community. ASI includes only a small amount of language information, and only to the state level. Omid provides a comprehensive picture for all of South Asia, as the data is coded to show all countries of residence for each community.
Joshua Project uses Omid data exclusively for India, Nepal, Pakistan, Bangladesh, Bhutan, and Sri Lanka. The Omid data for Sri Lanka needs to be re-worked, and Joshua Project does not use the district or state level data for this country.
The IMB's CPPI list had much of its origin in Omid's "Blue Book", which the India Missions Association published in 1997. The IMB's field staff use a different list than CPPI, which they refer to as the Prem list. The Prem list is derived from the ASI list.
In addition to these lists of communities, the World Christian Database and the Ethnologue provide lists of language groups (WCD subdivides some of these language groups). These valuable lists provide an alternative view of the people of South Asia, especially useful for language-focused outreach. Lists by community are critical for church planting, and lists by language are needed for language based ministry.