When overlays are transmitted by facsimile, only black and white are possible. Use the
abbreviation EN to indicate enemy locations.
4. Use of Fields.
A field is a designated area around a basic symbol that you use to display a particular item of
information. This information may be another symbol (such as a size indicator), words, or letters.
Some fields only apply to friendly forces; others only apply to enemy forces. You position the fields
around the basic symbol to provide the necessary amplifying information. Some fields are mandatory,
others are optional. See appendix B for a detailed description of fields (App B, p B-77), and how you
use them to clearly and concisely depict the information conveyed by the symbol. Figure 1-12 shows
how you develop fields around the basic symbol.
Figure 1-12. Use of fields
5. Symbols for Location.
You use basic unit and installation symbols to indicate their location. The center of the mass of the
symbol indicates the general vicinity of the center of the unit. If you need to indicate a location more
precisely, use the basic symbol mounted on a staff, which you extend or bend so that the end of the
staff points to the precise location.
You may want to include dates and times under or inside your symbol for such items as opening an
observation post or the expected establishment of a unit headquarters (HQ). You use solid line symbols
to represent a present or actual location.