
Miracode is a slightly modified version of the Soundex indexing format. Miracode and Soundex are indexes based on the pronunciation of a name, rather than the name's spelling. Surnames are coded and then arranged numerically by their codes. Miracode system was used only for 1910 for the following states: Alabama, Arkansas, California, Florida, Georgia, Illinois, Kansas, Kentucky, Louisiana, Michigan, Mississippi, Missouri, North Carolina, Ohio, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, and West Virginia. For more information, see the following article in Ancestry's reference library: http://www.ancestry.com/library/view/news/articles/2253.asp
The omission rate in the 1910 Miracode/Soundex appears to be greater than in most other indexes. Not everyone enumerated on the 1910 census schedules is on the Miracode indexes, as some names were missed or misread by the indexer. It is especially advisable for researchers to continue a search in the actual schedules, even when a name fails to appear in an index.