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Standard ST.7

Version 1.0

Revision adopted by the PCIPI Executive Coordination Committee at its twenty–second session on May 28, 1998


Editorial note
by the International Bureau published in March 2007

The microform technology covered by the series of WIPO Standards ST.7, ST.7/A, ST.7/B, ST.7/C, ST.7/D, ST.7/E, and ST.7/F has been replaced with new IT products (e.g., CD‑ROM, DVD, etc.) since these Standards were first adopted during the 1980's. Therefore, due to the very limited use of this media by industrial property offices, no further review of these Standards has been carried out since the year 2000 (e.g., according to the decisions by the SCIT Standards and Documentation Working Group, at its second session, on December 6, 2002, Standard ST.7/A was not updated to incorporate revision to Standard ST.6; according to the decisions by the SCIT Standards and Documentation Working Group, at its fourth session, on January 30, 2004, Standards ST.7/A and ST.7/E were not updated to incorporate revision to Standard ST.8). It is not expected that any additional offices will be providing data on this media in the future. (See paragraph 51 of document SCIT/SDWG/8/14.)




In this Handbook, “microforms” is the generic term used to indicate all types of carriers upon which photographic images are recorded. It includes, inter alia, roll film, film strips per se, film strips in jacket, microfiche, and aperture cards.


The use of microforms in Patent Offices offers a means of solving the problem of the vast amount of space needed for the storage of paper copies of patent documents and of minimizing the cost of exchanging copies of such documents. However, the technology covered by Standards ST.7/A to 7/F is increasingly being replaced by CD‑ROM products. Therefore, no further review of those Standards is expected to be carried out after the year 2000. With respect to the use of CD‑ROM products, reference is made to WIPO Standard ST.40 “Recommendation Concerning Making Facsimile Images of Patent Documents Available on CD‑ROM”.

Review of activities


PCPI activities in the field of microforms have resulted in the establishment of the following recommendations:

(a) 8‑up Aperture Card Microform (Standard ST.7/A);

(b) Recommended Standard for 16 mm Roll Microfilm for Exchange between Patent Offices (Standard ST.7/B);

(c) Recommended Standard for 35 mm Roll Microfilm in 8‑up Configuration for Exchange between Patent Offices (Standard ST.7/C);

(d) Recommendation for a Standardized Method of Identifying Roll Microfilm Files of Patent and Patent‑Related Documents (Standard ST.7/D);

(e) Guidelines for Photo‑Optically Generated Microfiches (Standard ST.7/E);

(f) Guidelines for Computer Output Microfiches (COM) (Standard ST.7/F).

Definitions of terms used in respect of micrographics for the purposes of this series of recommendations *


Film width, generally expressed in millimeters.

Film type

Silver‑halide: A film which is coated with an emulsion consisting of a compound of silver and one of the following elements known as halogens: chlorine, bromine, iodine, fluorine;

Diazo: A slow print film, sensitized by means of diazonium salts which, subsequent to exposure to light strong in the blue to ultraviolet spectrum and development, forms an image. Diazo films generally produce irreversible images, i.e., a positive image will produce a positive image and a negative image will produce a negative image;

Vesicular: A film which has the light sensitive element suspended in a plastic layer and which upon exposure creates strains within the layer in the form of a latent image. The strains are released and the latent image made visual by heating the plastic layer. The image becomes permanent when the layer cools.


A measure of the remoteness of a particular copy from the original material. The picture taken of a document, cathode ray tube, etc. is termed first generation microfilm (camera microfilm). Copies made from this first generation are second generation, and copies from the second generation are third generation, etc.


A word used to indicate the change or retention of the dark to light relationship of an image, i.e., a first generation negative to a second generation positive indicates a polarity change while a first generation negative to a second generation negative indicates that polarity is retained.

Positive: Polarity of a photographic image with dark lines, characters and neutral tones on a light background;

Negative: Polarity of a photographic image with light lines, characters and neutral tones on a dark background.

Reduction ratio

The ratio of the linear measurement of a document to the linear measurement of the image of the same document expressed as 16:1, 20:1, etc.

Image orientation

The arrangements of images with respect to the edges of the film.

Image positioning technique

Simplex: Image‑positioning technique in rotary camera microfilming. Images are photographed across the full width of the film;

Duplex: Image‑positioning technique in rotary camera microfilming. Through the use of mirrors or prisms, an image of the front site of a document is photographed on one‑half of the film while an image of the back side of the same document is photographed simultaneously on the other half of the film;

Comic strip: Image‑positioning technique according to which images are photographed along the axis of the film;

8‑up: Image‑positioning technique on a 35 mm microfilm which permits eight 8.5 x 11 inch (approximately) documents to be filmed within a single microfilm frame.

Photographic quality of dissemination copy

Resolution: Measure of sharpness of a photographic image, expressed as the number of lines per millimeter, discernible in that image;

Density: The light‑absorbing quality of a photographic image usually expressed as the logarithm of the opacity;

Contrast: An expression of the relationship between the high and low density of a photographic image;

Degree of archival quality: The degree to which a film retain its characteristics during a period of use and storage.

[End of Standard]

[WIPO Standard ST.7/A]

* The “Glossary of Micrographics”, publication MS 100‑1971 issued by the National Microfilm Association, USA, has been used as a basis for defining the English terms.