PORTLAND – Fifteen gay couples and four unmarried heterosexual couples have obtained domestic-partner status since Portland began recognizing same-sex and opposite sex couples as families a month ago.

The registry extends to same-sex and unmarried couples of opposite sex many of the same rights enjoyed by married couples. For instance, they qualify for any city program or benefit offered to married couples.

“We did it because I guess it’s finally some official recognition that we made a commitment to each other,” Joseph Stackpole said of himself and his partner of nearly five years, Richard Johnson.

Brenda Buchanan, a Portland attorney who helped create the domestic partner ordinance, said she has heard a number of her clients mention interest in the registry.

“It’s hugely important to gay couples who don’t have any other option,” she said. “When people realize the numbers, they see that these couples exist.”

To be eligible for the registry, applicants may not be married, must be at least 18 years old and be Portland residents. Applicants must identify any dependents.

To be registered in Portland, both partners must go to City Hall and, in the presence of a clerk, fill out a form that asks eight questions about the status and duration of their relationship.

Each partner must also show a picture identification and proof of joint residency, either on a driver’s license, lease agreement, bank record or three pieces of mail. The applicants then are placed under oath before signing the registry.

Some couples also may pay an additional $50 for a more formal registry signing in the State of Maine room. However, no couple has chosen that ceremony.