There are three criteria of defining legal issues in Islamic jurisprudence (fiqh):
Shari : Something that is clearly defined in the shariah.
'Urfi : Conventional or common tradition. An 'Urfi definition is acceptable to the common people without any scientific or shari precision.
Ilmi : A definition presented by science.
If the shariah defines something, all Muslims must follow that definition. If the shariah is silent on an issue, Muslims should follow the 'Urfi definition. (Source: Sayyid Muhammad Rizvi, Marriage and Morals in Islam, Chapter Four)
The 'Urfi marriage is a marriage without an official contract. Couples repeat the words, "We got married" and pledge commitment before God. Usually a paper, stating that the two are married, is written and two witnesses sign it. The Egyptian government did not recognized 'Urfi marriages until 2000 and the paper could be used only to prove the relationship in court. A women could not get a divorce since the government did not recognize the marriage in the first place. Under the new personal status law passed on January 29, 2000 however, divorces from 'Urfi marriages are now recognized.
According to Madiha Al Safty (Professor of Sociology at the American University in Cairo), the 'Urfi marriage has always existed, but for different reasons.
Undocumented 'Urfi marriages are increasingly popular among Egyptian youth. The high cost of marriage forces many young couples to wait several years before they marry. Conservative Egyptian society forbids sex before marriage, so many young people consider the 'Urfi marriage a solution. 'Urfi marriages are conducted by a Muslim cleric in the presence of two witnesses. However, they are not officially registered and are not financially binding on the man. Couples married in this way often meet in secret and avoid the expense of renting an apartment. The 'Urfi marriage can be disastrous for the wife. If the husband leaves her without granting her a divorce, she had no legal right to seek a divorce since 'Urfi marriage was considered illegal under the old status law. Her husband could remarry. The wife is in a more difficult position. If the wife remarries, she can be accused of polyandry which is punishable by seven years in prison in Egypt, or she could remain single for the rest of her life.
The new Egyptian law (passed in 2000) recognizes the woman's right to seek divorce from an 'Urfi marriage. However, the law denies her alimony and child support.
There are also controversial, unofficial "'Urfi" marriages, where a couple signs documents declaring themselves married. The couple does not inform their families of the marriage. Many Egyptian clerics are against this type of 'Urfi marriage calling it a cover for pre-marital sex.
An extreme form of 'Urfi marriage is known as zawag al-'urfi:
Other articles: Mut'a Marriage, Misyar Marriage, Part-time Marriages (newspaper article)
Further reading: Women in Islam