This subseries consists of negatives, both individual frames and strips of 3 or 4 frames, which were numbered by the creator and placed into numerical series based on subject and/or location. The arrangement is not necessarily chronological but does accurately represent intellectual distinctions between subjects. For example, all 3000s are images of San Cristóbal de las Casas but they are numbered regardless of the year in which they were photographed.

Strips of three or four frames were numbered according to their content and then cut into single negatives and sleeved individually with their corresponding number. However, a number of strips were numbered but not cut, and so whole series exist piecemeal in two locations and as two formats: in folders as strips, and in box divisions as single, sleeved negatives. A number of the sleeved negatives have hand-written information in addition to number and location, including the year, topic, and name of the subject.

In addition to numbering based on the place where the photograph was taken, Hilt was also creating two artificial series called Portraits and Miscellaneous. Portraits of friends, companions and local peoples were singled out from other series and combined. For example, a strip of negatives from the Santa María Magdalena Aldama series is numbered 911, 5025, 912, 5026. The 900s represent the Santa María series, while the 5000s were intended to become part of the Portrait series. Since the process was not complete, these negatives were not separated and sleeved individually. Notes on the file or division level reflect what other numbers (and thus what other subjects) are present in that folder or division.

Whole sets of numbers, such as 700-800, were never used. In some cases, numbers are missing and the sequences are not complete. This suggests that some negatives were removed from the collection or numbers were overlooked due to human error. When numbers are not present in a folder or division they are noted in parentheses.

Irregularity in the numbering of series is present. For example, the 2000s: Najá series consists of 425 numbers, but there are in fact 446 negatives. This discrepancy arises because there are 3 missing negatives, 2 un-numbered negatives, 10 "5000 series" negatives, and 12 duplicate numbers. These factors exist elsewhere.

Additionally, many negatives were labeled but not numbered or have no information at all. In these instances the negatives became part of a separate subseries (Subseries 2B: Non-Sequential Negatives). Researchers looking for the complete treatment of a single subject or place should not overlook the un-numbered negatives.

Physical note: Negatives are arranged in numerical order. Researchers are asked to take care when handling the materials in order to retain their proper arrangement.

This subseries consists of negatives that were not assigned numbers as part of the larger sequential organization of the collection, or have no labeling of any kind. A numerical arrangement has been provided for physical control, but does not reflect an intellectual or chronological order.

Subjects (especially those of the Unlabeled negatives) range the entire breadth of the series including religious celebrations, friends in San Cristóbal de las Casas, local flora, one image of the Lacandón and some images of Gertrude Doby Blom and her residence at Na Bolom.

Physical note: Negatives are arranged in numerical order. Researchers are asked to take care when handling the materials in order to retain their proper arrangement. In the case of single, sleeved negatives, subjects and assigned numbers are written in pencil on the back of the negative envelopes.

The negatives are grouped by subject as described by the creator; notes at the file level indicate when the subject was not provided by the creator.