Same-sex unions

A civil union, also referred to by a variety of other names, is a legally recognized arrangement similar to marriage. These unions have been established in a number of countries since the late 1990s, often developing from less formal domestic partnership legislation. In Denmark, Finland, Iceland, Norway and Sweden, they have since been replaced, and in a number of other countries supplemented, by same-sex marriage. Civil unions are often seen by campaigners as a "first step" towards legalizing marriage for same-sex couples. While civil unions are predominantly established for both opposite-sex and same-sex couples, in a number of countries they are available to same-sex couples only.

Beginning with Denmark in 1989, civil unions under one name or another have been established by law in several, mostly developed, countries in order to provide legal recognition of relationships formed by unmarried same-sex couples and to afford them rights, benefits, tax breaks, and responsibilities similar or identical to those of legally married couples. In Brazil, civil unions were first created for opposite-sex couples in 2002, and then expanded to include same-sex unions through judicial decision nine years later.

Many jurisdictions with civil unions recognize foreign unions if those are essentially equivalent to their own; for example, the United Kingdom lists equivalent unions in Civil Partnership Act Schedule 20. Same-sex marriages performed abroad are commonly recognised as civil unions in jurisdictions that only have the latter.

The terms used to designate civil unions are not standardized, and vary widely from country to country. Government-sanctioned relationships that may be similar or equivalent to civil unions include civil partnerships, registered partnerships, domestic partnerships, significant relationships, reciprocal beneficiary relationships, common-law marriage, adult interdependent relationships, life partnerships, stable unions, civil solidarity pacts, and so on. The exact level of rights, benefits, obligations, and responsibilities also varies, depending on the laws of a particular country. Some jurisdictions allow same-sex couples to adopt, while others forbid them to do so, or allow adoption only in specified circumstances.

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