by anthropologists as fictive kinship include compadrazgo relations, foster care, common membership in a unilineal descent group, and legal adoption. A noted Gurung tradition is the institution of "Rodi", where teenagers form fictive kinship bonds and become Rodi members to socialize, perform communal tasks, and find marriage partners. In Western culture, a person may refer to close friends of one's parents as "aunt" or "uncle" (and their children as "cousin"), or may refer to close friends as "brother" or "sister", although this is just a mere courtesy treatment and does not represent an actual valuation as such. In particular, college fraternities and sororities in some North American cultures usually use "brother" and "sister" to refer to members of the organization. Monastic, Masonic, and Lodge organisations also use the term "Brother" for members. "Nursing Sister" is used to denote a rank of nurse, and the term "Sisterhood" may be used for feminists. Fictive kinship was discussed by Jenny White in her work on female migrant workers in Istanbul. In her work, she draws on ideas of production and the women she works with being drawn together through "webs of indebtedness" through which the women refer to each other as kin. These relationships are, however, less frequent than kin relationships, and serve purposes that are neither comparable to nor exclude a natural family. Compadrazgo is a form of fictive kinship that is rooted in Central Mexico history for many years. Literally meaning "co-parenthood", compadrazgo is a term to describe the set of relationships between a child, their parents, and their godparents. It has been hypothesized that these relationships evolved after the Spanish conquest in 1521 to help deal with stressful situations. These fictive kinships still exist in modern day Mexican societies, and are established by providing some form of aid throughout the child's life. Godparents seldom become more important than parents, though, much less in a non-economic fashion. The boys and men of many societies have customs of "blood brotherhood" in which two unrelated people are declared to be as brothers. Perhaps the best-known such relationship in English-language literature is between the characters Tom Sawyer and Huckleberry Finn in the 1876 novel The Adventures of Tom Sawyer by American author Mark Twain, in a written agreement ritually signed in the parties' blood and deemed to have supernatural consequences. Mongolian Khagan-Emperor Genghis was to fellow aristocrat and political rival Jamukha, though the rivalry