Yichus

first appeared in the Hebrew Bible in the Book of Ezra. It appears in and ), where the Hebrew root (yud-chet-sin) means "relation to" or "related to." Although the word originated in Hebrew, and .{{cite web ==History==

As far back as the Talmudic era, being son-in-law to someone widely respected was valued. Subsequently, even the of being son-in-law to the son-in-law and similar lineage links were valued. From the 14th century onwards, was an important concern for Eastern European Jews. There was a tension between on one hand, and "meritocratic leadership based on scholarship" on the other. and reformers criticized for leading to inbreeding within small circles of "acceptable" families. The family trees, or pedigree charts, of Jewish families, listing genealogy and family history records, have been identified with several names, among which are yichus book, and yichus record. is not as extensive as a yichus book whereas a yichus book or yichus record/"sefer yuchsin"/registry is community-oriented. Some families also kept a separate "Register of Circumcisions". ==Types==

Being the (מְחוּתָּן, father of one's child's spouse) of a notable person is sometimes considered important enough to include in a wedding invitation and in giving other credentials. Although primarily used for same generation relatives, it can be used beyond that generation. Being a (literally son-after-son, i.e. patrilineal) descendant is sometimes considered more notable than other forms of descent.{{cite web For various reasons, surnames/family names were changed, and sometimes reverted. Thus, Jewish family names have not always been a reliable indicator of ancestry. For example: certain family names, such as Cohen, are not as strongly indicative of being a Kohen as Katz. ==References==