From Dean Wilson at the Southwest Ceramic Typology Project: Reserve Black-on-white was defined by Nesbitt (1938). This type refers to Cibola white ware pottery exhibiting very widespread styles common in the southernmost provinces of the Anasazi and northernmost provinces of the Mogollon (Crown 1981; Doyel 1980; Hays-Gilpin and van Hartesveldt 1998; Rinaldo and Bluhm 1956; Reid, Montgomery, and Zedeno 1995; Wilson 1999). This type appears to been produced from about A.D. 1000 to 1200 and spans a period during which a wide range of types including Escavada, Puerco, Gallup, and Chaco McElmo Black-on-white were produced in areas of the Cibola or Chaco region to the north. In areas of the Southern Cibola, pottery such characteristics appear to be transitional between Red Mesa and Tularosa Black-on-white. Examples assigned to the Puerco Valley variety of this type exhibit porous gray, dark gray or gray-brown pastes indicative of the use of high iron clays and abundant sherd temper.

From Oppelt (2007): 

This type is similar to Tularosa Black-on-white. It has thicker slip and is more evenly polished. Tularosa hatching lines are much finer. Tularosa also has more cross-
hatching and longitudinal hatching in addition to the oblique hatching. Reserve has only oblique hatching. The Reserve temper is fine to medium crushed sherd and fine quartz sand. The surface is well polished with a thin washy slip. The paint is iron-
based mineral. The main motifs are opposed solid and hatched elements similar to Wingate Black-on-red style. Hatched elements are larger than the solids. The framing lines are usually the same width as the hatching lines. A fairly common element is an open circle in a solid triangle with a dot in it with an opposing hatched element. Pitchers predominate, jars and rarely bowls, ladles and effigies are also present. Reserve Black-on-white is most abundant in the White Mountains of east-central Arizona. It is also found in the upper tributaries of the Blue, Black, Gila, San Francisco, Tularosa and Little Colorado rivers in east-central Arizona and west-central New Mexico.