Class 1 marking material covered by this specification is used in the manufacture of markers that are permanent in nature. The markers are then to be applied, by means of their adhesive layer, on exterior and interior surfaces of automotive vehicles, aerospace and ground support equipment, on interior surfaces of aircraft, and in other applications as required or permitted. Class 2 marking material is intended for use in preparation of temporary identification and instruction markers in shipment and storage of supplies and equipment as provided in MIL-STD-129. An important characteristic of class 2 material; e.g. in marking of vehicles during shipment and storage, is that it is readily removable even after extended weathering. These materials are not intended to be used on surfaces which become heated above 150°F. For exterior markers of the United States Air force aircraft, the applicable material is covered by MIL-P-38477 (USAF).

The pressure sensitive adhesive of type I material is of the aggressive tack type. Accordingly, under some circumstances, type I material markers are subject to premature contact and attendant difficulties. These difficulties may be countered or avoided by various devices, such as appropriate scoring of the liner, technique of placement, wet method of application (dilute detergent), and other methods that may be furnished by suppliers to assist in proper positioning of markers of all sizes.

Type II material has been included in this specification for use primarily in large, difficult-to-apply markers when desired. Its pressure sensitive adhesive is of a type which confers a degree of positionability of the marker during application and prior to final attachment, and is desired by some users under certain conditions, particularly for markers like stars, crosses, letters, 16 inches or larger in size. Users should take note of the fact that the adhesion of type II material is significantly less than that of type I, and that use of this type will involve a trade-off of adhesion for positionability. It is expected that selection of the desired type will be governed by the user's experience and consideration of various factors, e.g., size and shape or configuration of marker, temperature during application, lesser adhesion of type II, difference in cost, skill of applicator.

Type III material is intended for mounting on metal or wood bases by a heat-vacuum process, e.g., as in manufacture of signs and makers.

In addition to their use in transferring legends and pre-spaced letters, translucent transfer sheets are incorporated in some markers to make use of other capabilities such as stiffening the markers for handling, masking markers from subsequent painting, and protecting marker surfaces from dirt and foreign matter, as may be required.