The finds at Ayub Cave in South Cotabato confirmed the great pottery tradition of the Philippines. In the Tokiko it mentions that all Rusun jars had this marking known as the rokuru (wheel mark). Those familiar with Philippine ethnography will know that this spiral is commonly used by many of the Philippine tribes. The following symbols were used to identify which kiln was used to make the jar: identified "Imbe" jars, meant jars coming from Bizen kiln, and mark three times meant a canister from the same oven. A jar with this mark is said to be made of Namban clay. This marking corresponds to the syllable la in Pampanga; Tagbanua for ka ("Chinese Pottery," Field Museum of Natural History-Anth., vol.xii, Jul.1912) Of course, the symbol for la can also be the same as that for lu, and so this might correspond to the symbol said to stand for Lu in Rusun-no kokuji (Luzon national writing). According to the Tokiko, certain types of Rusun jars were distinguished by this character. De Morga mentions that Japanese traders were still coming in large numbers for these jars during his time, and that they were willing to spend great sums for them. Apparently work on these jars continued in the North, possibly among the unconquered Igorots, for De Morga had no knowledge of such current production. Later, the knowledge may have again trickled down to Vigan, where a flourishing industry of Burnay jar manufacture survives to this day. Although the Japanese described very high quality jars coming from the Philippines, not all were of elegant nature. In fact, De Morga had some disdain for some of the jars that the Japanese were buying, so they could have been similar to the well-known balanga and other jars in use today. These jars are generally handed down as heirlooms and are noted for their qualities in enhancing the fermentation process. Possibly one of the Japanese uses for the Rusun jars was fermentation of products like Kombucha and Umeboshi plums. For instance, a Japanese family in rural Japan stated that their family used old Rusun jars for exactly this purpose up to this day.