Boston ? Gay couples traveling overseas can now show passports that feature their married names, letting them take advantage of a little-noticed revision to State Department regulations that critics had feared would undermine the federal Defense of Marriage Act.

The notice of the change says that it does not mean the State Department is recognizing the validity of same-sex marriages and civil unions, but that it was to comply with an amendment to the Code of Federal Regulations that took effect in February 2008.

The name-change revision took effect May 27 in an addition to the State Department’s Foreign Affairs Manual. It allows same-sex couples to obtain passports under the names recognized by their state through their marriages or civil unions.