Direct Consular Filing (DCF) is a process related to immigration to the United States whereby Form I-130 (Petition for Alien Relative), I-360 (Petition for Amerasian, Widow(er), or Special Immigrant), or I-600 (Petition to Classify Orphan as an Immediate Relative), is filed with a United States embassy or consulate in another country rather than with the United States Citizenship and Immigration Services lockbox or service center facilities located within the US.
DCF is available only under exceptional circumstances and can only be done in the country where the petitioner (who, in the case of Forms I-130 and I-600, is distinct from the eventual visa applicant) legally resides.
However, there are some exceptions: The DCF petitioner must reside legally in the consular district of the U.S. Embassy or Consulate at which he or she is requesting to file.
[1] The embassy or consulate that processes the Form I-130 petition may differ from the one whose consular district the petitioner applies from (which is also where the applicant will appear for the visa interview), because not all embassies or consulates in a country can process DCF petitions.
For instance, in India, only the Delhi embassy can process DCF petitions.