Jacob Wolphertszoon's ship was called a Scots frigate

I was interested to see that, in the list of ships of the Admiralty of Zeeland in late 1652, Jacob Wolphertszoon's ship, the Sint Joris (St. George) was described as a Scots frigate. The Sint Joris was a very small ship, just 90ft in length, with a main armament of 6pdr guns.