I found two photographs online showing the same flag, that I believe is likely the municipal flag for the city of Moca. Alternatively, it could be the flag of Espaillat province instead, being used at functions to represent Moca. Both photographs show a coat of arms centered on a white field. The coat of arms features a cornucopia in proper colors on an argent shield, shown on the flag as white. There are words arched above the shield in a dark blue cursive script, but I am unable to read them. I believe there may be additional words below the shield as well. I have found references online to that particular coat of arms representing both Moca and Espaillat, so I'm not sure to which entity the flag would belong. Right now, I lean toward Moca city rather than Espaillat province. Hopefully, though, someone could shed some additional light on this question.
I have not yet giffed the flag, but the photographs can be found online here and here. Randy Young, 19 December 2015
Moca is the capital city of Espaillat province in the north central part of the country. While the true root of the city's name is unknown, it has a rather illustrious history of famous, patriotic citizens, earning it the nickname "La Villa Heroica," or Village of Heroes.
Source: Wikipedia article Randy Young, 19 December 2015