Guide to Map Details
A number of codes have been used to designate various aspects of each map's bibliographic description. An explanatory list of these codes and other descriptive conventions is provided below.
c circa date -- no date on the map. Date is derived from information on the map.
a assigned by staff, based on information available in addition to the map
(no code) date taken directly from the map
also includes the agency responsible for the creation or production of the map
st. statute miles
b&w black and white
blueline blue on white
blueprint white on blue
brown line brown on white
other reproduction process not listed here
ph-p positive photostat, black on white
photostat white on black
purple line purple on a light background
slide 35 mm slide
trans. photographic positive transparency
ag agricultural map
bird birdseye view
gen general map
geo geologic map
hwy highway map
nau nautical chart
o&g oil and gas map
out outline map
own ownership map
relf relief map
rr railroad map
stat statistical map
str street map
sur survey map
topo topographic map
tran transportation map (focus not on railroads or general highways)
wea weather & weather related info
Record Group or Series
The record group number assigned to state agencies is sometimes used in this field. For instance the number 017.8 refers to maps in Texas Planning Board records, series 8.
For manuscript collections, the series number or title is given following the title of the collection, e.g., James H. Holdeman Papers, series 7
If the records or papers are unprocessed, a series designation is not given.
An accession number is assigned when the map is received and is used as a control number.
(other languages follow this format)