Fields (items) in coverage attribute tables

Coverage attributes are stored in INFO files, typically with an .adf extension, in the coverage folder. The specification of the format for each record in the data file is referred to as the item definition. In ArcGIS, items are more commonly known as fields, attributes, or columns in a table.

Each record in a coverage attribute (INFO) table can have up to 4,096 characters (that is, bytes). This is the sum of the input widths of the items in the attribute table. Any number of items can be defined for the data file. Items are defined by their name, data type, number of characters (or bytes) used to store values, display width, and (for decimal numbers) number of decimals you want to display.

INFO uses the following conventions to define the format of each item (field) in a data file:

Item format	Description
Item name	Any name with up to 16 alphanumeric characters
Item width	Number of spaces (or bytes) used to store item values
Output width	Number of spaces (or bytes) used to display item values
Item type	The data type of the item
Number of decimals	The number of digits to the right of the decimal place for item types that hold decimal numbers

Item format definitions

Supported item types

The following INFO file item types are supported in ArcGIS:

INFO file item types	Description
B	Whole numbers are stored as binary integers (width of 2 or 4 bytes only). The maximum value for a width of 2 bytes is 32,767; a width of 4 bytes can have a maximum value of 2,147,483,647. The minimum value for a width of 2 is -32,768; for a width of 4, the minimum value is -2,147,483,648.
C	Character (width up to 320 alphanumeric characters).
D	Dates in the form DD/MM/YY or DD/MM/YYYY. The item width is fixed at 8 and stored internally as YYYYMMDD.
F	Decimal numbers are stored in internal floating-point representation (width of 4 or 8 bytes only). A 4-byte width is single precision (approximately 7 digits of precision), and 8 bytes is double precision (approximately 15 digits of precision).
I	Integers are stored as 1 byte per digit. The width can vary from 1 to 16. The maximum value possible is 9,999,999,999,999,998; the minimum is -999,999,999,999,999.
N	Decimal numbers stored as 1 byte per digit, with a width between 1 and 16.

Supported INFO types

Item definitions for aat.adf (arc attribute table)

Single-precision covers

Item name	Item width	Output width	Item type	Number of decimals
FNODE#	4	5	B	-
TNODE#	4	5	B	-
LPOLY#	4	5	B	-
RPOLY#	4	5	B	-
LENGTH	4	12	F	3
cover#	4	5	B	-
cover-ID	4	5	B	-

Single-precision covers

FNODE# is the internal number of the from-node.

TNODE# is the internal number of the to-node.

LPOLY# is the left polygon number (cover# in polygon attribute table).

RPOLY# is the right polygon number (cover# in polygon attribute table).

Cover# is the arc's internal number.

Cover-ID is the arc's User-ID.

Double-precision covers

Item name	Item width	Output width	Item type	Number of decimals
FNODE#	4	5	B	-
TNODE#	4	5	B	-
LPOLY#	4	5	B	-
RPOLY#	4	5	B	-
LENGTH	8	18	F	5
cover#	4	5	B	-
cover-ID	4	5	B	-

Double-precision covers

FNODE# is the internal number of the from-node.

TNODE# is the internal number of the to-node.

LPOLY# is the left polygon number (cover# in polygon attribute table).

RPOLY# is the right polygon number (cover# in polygon attribute table).

Cover# is the arc's internal number.

Cover-ID is the arc's User-ID.

Item definitions for pat.adf (point attribute table)

The point attribute table (PAT) is similar to the polygon attribute table (PAT); however, the AREA and PERIMETER values are zero for each point.

Single-precision covers

Item name	Item width	Output width	Item type	Number of decimals
AREA	4	12	F	3
PERIMETER	4	12	F	3
cover#	4	5	B	-
cover-ID	4	5	B	-

Point attribute table—Single precision

AREA is 0.

PERIMETER is 0.

Cover# is the point's internal number.

Cover-ID is the point's User-ID.

Double-precision covers

Item name	Item width	Output width	Item type	Number of decimals
AREA	8	18	F	5
PERIMETER	8	18	F	5
cover#	4	5	B	-
cover-ID	4	5	B	-

Point attribute table—Double precision

AREA is 0.

PERIMETER is 0.

Cover# is the point's internal number.

Cover-ID is the point's User-ID.

Item definitions for pat.adf (polygon attribute table)

Single-precision covers

Item name	Item width	Output width	Item type	Number of decimals
AREA	4	12	F	3
PERIMETER	4	12	F	3
cover#	4	5	B	-
cover-ID	4	5	B	-

Polygon attribute table—Single precision

AREA is the area of the polygon in coverage units.

PERIMETER is the perimeter of the polygon in coverage units.

Cover# is the polygon's internal number (LPOLY# and RPOLY# in arc attribute table).

Cover-ID is the polygon's User-ID.

Double-precision covers

Item name	Item width	Output width	Item type	Number of decimals
AREA	8	18	F	5
PERIMETER	8	18	F	5
cover#	4	5	B	-
cover-ID	4	5	B	-

Polygon attribute table—Double precision

AREA is the area of the polygon in coverage units.

PERIMETER is the perimeter of the polygon in coverage units.

Cover# is the polygon's internal number (LPOLY# and RPOLY# in arc attribute table).

Cover-ID is the polygon's User-ID.

Item definitions for tic.adf (tic table)

Single-precision covers

Item name	Item width	Output width	Item type	Number of decimals
IDTIC	4	5	B	-
XTIC	4	12	F	3
YTIC	4	12	F	3

Tic table—Single-precision covers

IDTIC is the User-ID of the tic.

XTIC is the x-coordinate of the tic.

YTIC is the y-coordinate of the tic.

Double-precision covers

Item name	Item width	Output width	Item type	Number of decimals
IDTIC	4	5	B	-
XTIC	8	18	F	5
YTIC	8	18	F	5

Tic table—Double-precision covers

IDTIC is the User-ID of the tic.

XTIC is the x-coordinate of the tic.

YTIC is the y-coordinate of the tic.

Item definitions for bnd.adf (coverage boundary table)

Single-precision covers

Item name	Item width	Output width	Item type	Number of decimals
XMIN	4	12	F	3
YMIN	4	12	F	3
XMAX	4	12	F	3
YMAX	4	12	F	3

Coverage boundary tables—Single-precision covers

XMIN and YMIN are the coordinates of the lower left corner of the minimum bounding rectangle of all arcs and points in the coverage.

XMAX and YMAX are the coordinates of the upper right corner of the minimum bounding rectangle of all arcs and points in the coverage.

Double-precision covers

Item name	Item width	Output width	Item type	Number of decimals
XMIN	8	18	F	5
YMIN	8	18	F	5
XMAX	8	18	F	5
YMAX	8	18	F	5

Coverage boundary tables—Double-precision covers

XMIN and YMIN are the coordinates of the lower left corner of the minimum bounding rectangle of all arcs and points in the coverage.

XMAX,YMAX are the coordinates of the upper right corner of the minimum bounding rectangle of all arcs and points in the coverage.

Item definitions for nat.adf (node attribute table)

Single- and double-precision covers

Item name	Item width	Output width	Item type	Number of decimals
ARC#	4	5	B	-
cover#	4	5	B	-
cover-ID	4	5	B	-

Node attribute tables—Single- and double-precision covers

ARC# is the internal number of the arc corresponding to the node.

Cover# is the node's internal number.

Cover-ID is the node's User-ID.

Item definitions for <route>.rat (route attribute table)

Single- and double-precision covers

Item name	Item width	Output width	Item type	Number of decimals
subclass#	4	5	B	-
subclass-ID	4	5	B	-

Route attribute tables—Single- and double-precision covers

Subclass# is the internal number of the route subclass.

Subclass-ID is the User-ID of the route subclass.

Item definitions for <route>.sec (section attribute table)

Single- and double-precision covers

Item name	Item width	Output width	Item type	Number of decimals
ROUTELINK#	4	5	B	-
ARCLINK#	4	5	B	-
F-MEAS	4	12	F	3
T-MEAS	4	12	F	3
F-POS	4	12	F	3
T-POS	4	12	F	3
subclass#	4	5	B	-
subclass-ID	4	5	B	-

Section attribute tables—Single- and double-precision covers

ROUTELINK# identifies the route to which the section belongs.

ARCLINK# identifies the arc that the section references.

F-MEAS is the start measure of the section.

T-MEAS is the end measure of the section.

F-POS and T-POS are the start points and endpoints of the section, expressed as a percentage along the arc from its from-node.

Subclass# is the internal number of the route subclass.

Subclass-ID is the User-ID of the route subclass.

Item definitions for <region>.pat (region attribute table)

Single-precision covers

Item name	Item width	Output width	Item type	Number of decimals
AREA	4	12	F	3
PERIMETER	4	12	F	3
subclass#	4	5	B	-
subclass-ID	4	5	B	-

Region attribute tables—Single-precision covers

AREA is the area of the region subclass in coverage units.

PERIMETER is the perimeter of the region subclass in coverage units.

Subclass# is the region's internal number.

Subclass-ID is the region's User-ID.

Double-precision covers

Item name	Item width	Output width	Item type	Number of decimals
AREA	8	18	F	5
PERIMETER	8	18	F	5
Subclass#	4	5	B	5
Subclass-ID	4	5	B	5

Region attribute tables—Double-precision covers

AREA is the area of the region subclass in coverage units.

PERIMETER is the perimeter of the region subclass in coverage units.

Subclass# is the region's internal number.

Subclass-ID is the region's User-ID.